21861464 has 16 divisors (see below), whose sum is σ = 41060520. Its totient is φ = 10912000.

The previous prime is 21861461. The next prime is 21861481. The reversal of 21861464 is 46416812.

It is a self number, because there is not a number n which added to its sum of digits gives 21861464.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21861461) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3464 + ... + 7464.

Almost surely, 2^21861464 is an apocalyptic number.

It is an amenable number.

21861464 is a deficient number, since it is larger than the sum of its proper divisors (19199056).

21861464 is a wasteful number, since it uses less digits than its factorization.

21861464 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4690 (or 4686 counting only the distinct ones).

The product of its digits is 9216, while the sum is 32.

The square root of 21861464 is about 4675.6244502740. The cubic root of 21861464 is about 279.6145376234.

The spelling of 21861464 in words is "twenty-one million, eight hundred sixty-one thousand, four hundred sixty-four".