21273964 has 12 divisors (see below), whose sum is σ = 38235904. Its totient is φ = 10349424.

The previous prime is 21273961. The next prime is 21273991. The reversal of 21273964 is 46937212.

It is a hoax number, since the sum of its digits (34) coincides with the sum of the digits of its distinct prime factors.

It is not an unprimeable number, because it can be changed into a prime (21273961) 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, 71724 + ... + 72019.

Almost surely, 2^21273964 is an apocalyptic number.

It is an amenable number.

21273964 is a deficient number, since it is larger than the sum of its proper divisors (16961940).

21273964 is a wasteful number, since it uses less digits than its factorization.

21273964 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 143784 (or 143782 counting only the distinct ones).

The product of its digits is 18144, while the sum is 34.

The square root of 21273964 is about 4612.3707569969. The cubic root of 21273964 is about 277.0869932293.

The spelling of 21273964 in words is "twenty-one million, two hundred seventy-three thousand, nine hundred sixty-four".