21280902 has 16 divisors (see below), whose sum is σ = 42984432. Its totient is φ = 7023200.

The previous prime is 21280891. The next prime is 21280907. The reversal of 21280902 is 20908212.

It is a Smith number, since the sum of its digits (24) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21280907) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 16953 + ... + 18164.

It is an arithmetic number, because the mean of its divisors is an integer number (2686527).

Almost surely, 2^21280902 is an apocalyptic number.

21280902 is an abundant number, since it is smaller than the sum of its proper divisors (21703530).

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

21280902 is a wasteful number, since it uses less digits than its factorization.

21280902 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 35223.

The product of its (nonzero) digits is 576, while the sum is 24.

The square root of 21280902 is about 4613.1228034814. The cubic root of 21280902 is about 277.1171117443.

The spelling of 21280902 in words is "twenty-one million, two hundred eighty thousand, nine hundred two".