21465136 has 120 divisors (see below), whose sum is σ = 55978560. Its totient is φ = 7862400.

The previous prime is 21465131. The next prime is 21465137. The reversal of 21465136 is 63156412.

It is a Harshad number since it is a multiple of its sum of digits (28).

It is not an unprimeable number, because it can be changed into a prime (21465131) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 163791 + ... + 163921.

It is an arithmetic number, because the mean of its divisors is an integer number (466488).

Almost surely, 2^21465136 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21465136, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27989280).

21465136 is an abundant number, since it is smaller than the sum of its proper divisors (34513424).

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

21465136 is a wasteful number, since it uses less digits than its factorization.

21465136 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 183 (or 170 counting only the distinct ones).

The product of its digits is 4320, while the sum is 28.

The square root of 21465136 is about 4633.0482406295. The cubic root of 21465136 is about 277.9145053942.

The spelling of 21465136 in words is "twenty-one million, four hundred sixty-five thousand, one hundred thirty-six".