21389476 has 12 divisors (see below), whose sum is σ = 37468620. Its totient is φ = 10684160.

The previous prime is 21389453. The next prime is 21389479. The reversal of 21389476 is 67498312.

It can be written as a sum of positive squares in 2 ways, for example, as 3326976 + 18062500 = 1824^2 + 4250^2 .

It is not an unprimeable number, because it can be changed into a prime (21389479) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3480 + ... + 7408.

It is an arithmetic number, because the mean of its divisors is an integer number (3122385).

Almost surely, 2^21389476 is an apocalyptic number.

It is an amenable number.

21389476 is a deficient number, since it is larger than the sum of its proper divisors (16079144).

21389476 is a wasteful number, since it uses less digits than its factorization.

21389476 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5294 (or 5292 counting only the distinct ones).

The product of its digits is 72576, while the sum is 40.

The square root of 21389476 is about 4624.8757821157. The cubic root of 21389476 is about 277.5875913197.

The spelling of 21389476 in words is "twenty-one million, three hundred eighty-nine thousand, four hundred seventy-six".