28972420 has 24 divisors (see below), whose sum is σ = 64421784. Its totient is φ = 10907136.

The previous prime is 28972417. The next prime is 28972423. The reversal of 28972420 is 2427982.

It is an interprime number because it is at equal distance from previous prime (28972417) and next prime (28972423).

It can be written as a sum of positive squares in 4 ways, for example, as 5391684 + 23580736 = 2322^2 + 4856^2 .

It is a super-2 number, since 2×28972420² = 1678802241312800, which contains 22 as substring.

It is a hoax number, since the sum of its digits (34) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (34).

It is not an unprimeable number, because it can be changed into a prime (28972423) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 42267 + ... + 42946.

It is an arithmetic number, because the mean of its divisors is an integer number (2684241).

Almost surely, 2^28972420 is an apocalyptic number.

28972420 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28972420 is an abundant number, since it is smaller than the sum of its proper divisors (35449364).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

28972420 is a wasteful number, since it uses less digits than its factorization.

28972420 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 85239 (or 85237 counting only the distinct ones).

The product of its (nonzero) digits is 16128, while the sum is 34.

The square root of 28972420 is about 5382.6034592937. The cubic root of 28972420 is about 307.1342557018.

It can be divided in two parts, 28972 and 420, that added together give a palindrome (29392).

The spelling of 28972420 in words is "twenty-eight million, nine hundred seventy-two thousand, four hundred twenty".