21425464 has 32 divisors (see below), whose sum is σ = 43660800. Its totient is φ = 9819360.

The previous prime is 21425431. The next prime is 21425471. The reversal of 21425464 is 46452412.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2439 + ... + 6985.

It is an arithmetic number, because the mean of its divisors is an integer number (1364400).

Almost surely, 2^21425464 is an apocalyptic number.

It is an amenable number.

21425464 is an abundant number, since it is smaller than the sum of its proper divisors (22235336).

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

21425464 is a wasteful number, since it uses less digits than its factorization.

21425464 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4603 (or 4599 counting only the distinct ones).

The product of its digits is 7680, while the sum is 28.

The square root of 21425464 is about 4628.7648460469. The cubic root of 21425464 is about 277.7431853575.

Adding to 21425464 its reverse (46452412), we get a palindrome (67877876).

The spelling of 21425464 in words is "twenty-one million, four hundred twenty-five thousand, four hundred sixty-four".