21396888 has 48 divisors (see below), whose sum is σ = 61003800. Its totient is φ = 6756480.

The previous prime is 21396887. The next prime is 21396899. The reversal of 21396888 is 88869312.

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21396883) by changing a digit.

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 11 ways as a sum of consecutive naturals, for example, 6453 + ... + 9188.

Almost surely, 2^21396888 is an apocalyptic number.

It is an amenable number.

21396888 is an abundant number, since it is smaller than the sum of its proper divisors (39606912).

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

21396888 is a wasteful number, since it uses less digits than its factorization.

21396888 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15672 (or 15665 counting only the distinct ones).

The product of its digits is 165888, while the sum is 45.

The square root of 21396888 is about 4625.6770315274. The cubic root of 21396888 is about 277.6196513480.

The spelling of 21396888 in words is "twenty-one million, three hundred ninety-six thousand, eight hundred eighty-eight".