21398604 has 24 divisors (see below), whose sum is σ = 50028720. Its totient is φ = 7118784.

The previous prime is 21398603. The next prime is 21398621. The reversal of 21398604 is 40689312.

It is not an unprimeable number, because it can be changed into a prime (21398603) 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, 5902 + ... + 8810.

It is an arithmetic number, because the mean of its divisors is an integer number (2084530).

Almost surely, 2^21398604 is an apocalyptic number.

It is an amenable number.

21398604 is an abundant number, since it is smaller than the sum of its proper divisors (28630116).

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

21398604 is a wasteful number, since it uses less digits than its factorization.

21398604 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3529 (or 3527 counting only the distinct ones).

The product of its (nonzero) digits is 10368, while the sum is 33.

The square root of 21398604 is about 4625.8625141697. The cubic root of 21398604 is about 277.6270727167.

The spelling of 21398604 in words is "twenty-one million, three hundred ninety-eight thousand, six hundred four".