21365156 has 12 divisors (see below), whose sum is σ = 37457868. Its totient is φ = 10662912.

The previous prime is 21365153. The next prime is 21365159. The reversal of 21365156 is 65156312.

It is an interprime number because it is at equal distance from previous prime (21365153) and next prime (21365159).

It can be written as a sum of positive squares in 2 ways, for example, as 12460900 + 8904256 = 3530^2 + 2984^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21365153) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2321 + ... + 6936.

It is an arithmetic number, because the mean of its divisors is an integer number (3121489).

Almost surely, 2^21365156 is an apocalyptic number.

It is an amenable number.

21365156 is a deficient number, since it is larger than the sum of its proper divisors (16092712).

21365156 is a wasteful number, since it uses less digits than its factorization.

21365156 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9838 (or 9836 counting only the distinct ones).

The product of its digits is 5400, while the sum is 29.

The square root of 21365156 is about 4622.2457745126. The cubic root of 21365156 is about 277.4823450067.

The spelling of 21365156 in words is "twenty-one million, three hundred sixty-five thousand, one hundred fifty-six".