28691620 has 48 divisors (see below), whose sum is σ = 62270208. Its totient is φ = 11098880.

The previous prime is 28691617. The next prime is 28691629. The reversal of 28691620 is 2619682.

28691620 = T₈₇ + T₈₈ + ... + T₅₅₆.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (28691629) 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 15 ways as a sum of consecutive naturals, for example, 123024 + ... + 123256.

It is an arithmetic number, because the mean of its divisors is an integer number (1297296).

Almost surely, 2^28691620 is an apocalyptic number.

28691620 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28691620 is an abundant number, since it is smaller than the sum of its proper divisors (33578588).

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

28691620 is a wasteful number, since it uses less digits than its factorization.

28691620 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 420 (or 418 counting only the distinct ones).

The product of its (nonzero) digits is 10368, while the sum is 34.

The square root of 28691620 is about 5356.4559178621. The cubic root of 28691620 is about 306.1387867737.

It can be divided in two parts, 2869 and 1620, that added together give a square (4489 = 67²).

The spelling of 28691620 in words is "twenty-eight million, six hundred ninety-one thousand, six hundred twenty".