21392080 has 20 divisors (see below), whose sum is σ = 49736772. Its totient is φ = 8556800.

The previous prime is 21392071. The next prime is 21392099. The reversal of 21392080 is 8029312.

It can be written as a sum of positive squares in 2 ways, for example, as 2521744 + 18870336 = 1588^2 + 4344^2 .

It is a tau number, because it is divible by the number of its divisors (20).

It is a congruent number.

It is an unprimeable number.

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 3 ways as a sum of consecutive naturals, for example, 133621 + ... + 133780.

Almost surely, 2^21392080 is an apocalyptic number.

21392080 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21392080 is an abundant number, since it is smaller than the sum of its proper divisors (28344692).

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

21392080 is a wasteful number, since it uses less digits than its factorization.

21392080 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 267414 (or 267408 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 25.

The square root of 21392080 is about 4625.1572946225. The cubic root of 21392080 is about 277.5988555626.

The spelling of 21392080 in words is "twenty-one million, three hundred ninety-two thousand, eighty".