21320902 has 8 divisors (see below), whose sum is σ = 32761512. Its totient is φ = 10400400.

The previous prime is 21320881. The next prime is 21320911. The reversal of 21320902 is 20902312.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a self number, because there is not a number n which added to its sum of digits gives 21320902.

It is a congruent number.

It is an unprimeable number.

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 3 ways as a sum of consecutive naturals, for example, 129924 + ... + 130087.

It is an arithmetic number, because the mean of its divisors is an integer number (4095189).

Almost surely, 2^21320902 is an apocalyptic number.

21320902 is a deficient number, since it is larger than the sum of its proper divisors (11440610).

21320902 is a wasteful number, since it uses less digits than its factorization.

21320902 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 260054.

The product of its (nonzero) digits is 216, while the sum is 19.

The square root of 21320902 is about 4617.4562261055. The cubic root of 21320902 is about 277.2906279909.

It can be divided in two parts, 21320 and 902, that added together give a palindrome (22222).

The spelling of 21320902 in words is "twenty-one million, three hundred twenty thousand, nine hundred two".