28931400 has 72 divisors (see below), whose sum is σ = 97167330. Its totient is φ = 7714560.

The previous prime is 28931381. The next prime is 28931407. The reversal of 28931400 is 413982.

It can be written as a sum of positive squares in 3 ways, for example, as 16695396 + 12236004 = 4086^2 + 3498^2 .

It is a tau number, because it is divible by the number of its divisors (72).

It is a hoax number, since the sum of its digits (27) coincides with the sum of the digits of its distinct prime factors.

It is not an unprimeable number, because it can be changed into a prime (28931407) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 6237 + ... + 9836.

Almost surely, 2^28931400 is an apocalyptic number.

28931400 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28931400 is an abundant number, since it is smaller than the sum of its proper divisors (68235930).

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

28931400 is a wasteful number, since it uses less digits than its factorization.

28931400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16095 (or 16083 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 27.

The square root of 28931400 is about 5378.7916858715. The cubic root of 28931400 is about 306.9892373511.

The spelling of 28931400 in words is "twenty-eight million, nine hundred thirty-one thousand, four hundred".