21413656 has 32 divisors (see below), whose sum is σ = 44827200. Its totient is φ = 9505440.

The previous prime is 21413647. The next prime is 21413677. The reversal of 21413656 is 65631412.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 955 + ... + 6613.

It is an arithmetic number, because the mean of its divisors is an integer number (1400850).

Almost surely, 2^21413656 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 21413656, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22413600).

21413656 is an abundant number, since it is smaller than the sum of its proper divisors (23413544).

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

21413656 is a wasteful number, since it uses less digits than its factorization.

21413656 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5719 (or 5715 counting only the distinct ones).

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

The square root of 21413656 is about 4627.4891680046. The cubic root of 21413656 is about 277.6921527140.

The spelling of 21413656 in words is "twenty-one million, four hundred thirteen thousand, six hundred fifty-six".