21386902 has 4 divisors (see below), whose sum is σ = 32080356. Its totient is φ = 10693450.

The previous prime is 21386879. The next prime is 21386917. The reversal of 21386902 is 20968312.

It is a semiprime because it is the product of two primes.

It is a super-3 number, since 3×21386902³ (a number of 23 digits) contains 333 as substring.

It is a Smith number, since the sum of its digits (31) 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 an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5346724 + ... + 5346727.

It is an arithmetic number, because the mean of its divisors is an integer number (8020089).

Almost surely, 2^21386902 is an apocalyptic number.

21386902 is a deficient number, since it is larger than the sum of its proper divisors (10693454).

21386902 is a wasteful number, since it uses less digits than its factorization.

21386902 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10693453.

The product of its (nonzero) digits is 5184, while the sum is 31.

The square root of 21386902 is about 4624.5974959990. The cubic root of 21386902 is about 277.5764559507.

The spelling of 21386902 in words is "twenty-one million, three hundred eighty-six thousand, nine hundred two".