21392976 has 80 divisors (see below), whose sum is σ = 62281728. Its totient is φ = 6268800.

The previous prime is 21392971. The next prime is 21392989. The reversal of 21392976 is 67929312.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21392971) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 15715 + ... + 17021.

Almost surely, 2^21392976 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 21392976, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31140864).

21392976 is an abundant number, since it is smaller than the sum of its proper divisors (40888752).

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

21392976 is a wasteful number, since it uses less digits than its factorization.

21392976 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1360 (or 1354 counting only the distinct ones).

The product of its digits is 40824, while the sum is 39.

The square root of 21392976 is about 4625.2541551789. The cubic root of 21392976 is about 277.6027312197.

It can be divided in two parts, 2139 and 2976, that added together give a palindrome (5115).

The spelling of 21392976 in words is "twenty-one million, three hundred ninety-two thousand, nine hundred seventy-six".