21851464 has 16 divisors (see below), whose sum is σ = 41062320. Its totient is φ = 10901520.

The previous prime is 21851461. The next prime is 21851503. The reversal of 21851464 is 46415812.

It is not an unprimeable number, because it can be changed into a prime (21851461) 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, 1147 + ... + 6709.

It is an arithmetic number, because the mean of its divisors is an integer number (2566395).

Almost surely, 2^21851464 is an apocalyptic number.

It is an amenable number.

21851464 is a deficient number, since it is larger than the sum of its proper divisors (19210856).

21851464 is a wasteful number, since it uses less digits than its factorization.

21851464 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6060 (or 6056 counting only the distinct ones).

The product of its digits is 7680, while the sum is 31.

The square root of 21851464 is about 4674.5549520783. The cubic root of 21851464 is about 279.5718968099.

The spelling of 21851464 in words is "twenty-one million, eight hundred fifty-one thousand, four hundred sixty-four".