21398464 has 28 divisors (see below), whose sum is σ = 44311824. Its totient is φ = 10233344.

The previous prime is 21398453. The next prime is 21398467. The reversal of 21398464 is 46489312.

It is a Smith number, since the sum of its digits (37) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21398467) 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, 5797 + ... + 8740.

Almost surely, 2^21398464 is an apocalyptic number.

It is an amenable number.

21398464 is an abundant number, since it is smaller than the sum of its proper divisors (22913360).

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

21398464 is a wasteful number, since it uses less digits than its factorization.

21398464 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14572 (or 14562 counting only the distinct ones).

The product of its digits is 41472, while the sum is 37.

The square root of 21398464 is about 4625.8473818318. The cubic root of 21398464 is about 277.6264672586.

The spelling of 21398464 in words is "twenty-one million, three hundred ninety-eight thousand, four hundred sixty-four".