21392380 has 24 divisors (see below), whose sum is σ = 45391248. Its totient is φ = 8467968.

The previous prime is 21392359. The next prime is 21392381. The reversal of 21392380 is 8329312.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21392381) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3574 + ... + 7453.

It is an arithmetic number, because the mean of its divisors is an integer number (1891302).

Almost surely, 2^21392380 is an apocalyptic number.

21392380 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21392380 is an abundant number, since it is smaller than the sum of its proper divisors (23998868).

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

21392380 is a wasteful number, since it uses less digits than its factorization.

21392380 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11133 (or 11131 counting only the distinct ones).

The product of its (nonzero) digits is 2592, while the sum is 28.

The square root of 21392380 is about 4625.1897258383. The cubic root of 21392380 is about 277.6001532277.

The spelling of 21392380 in words is "twenty-one million, three hundred ninety-two thousand, three hundred eighty".