21542964 has 12 divisors (see below), whose sum is σ = 50266944. Its totient is φ = 7180984.

The previous prime is 21542959. The next prime is 21542977. The reversal of 21542964 is 46924512.

It is a tau number, because it is divible by the number of its divisors (12).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 897612 + ... + 897635.

It is an arithmetic number, because the mean of its divisors is an integer number (4188912).

Almost surely, 2^21542964 is an apocalyptic number.

It is an amenable number.

21542964 is an abundant number, since it is smaller than the sum of its proper divisors (28723980).

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

21542964 is a wasteful number, since it uses less digits than its factorization.

21542964 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1795254 (or 1795252 counting only the distinct ones).

The product of its digits is 17280, while the sum is 33.

The square root of 21542964 is about 4641.4398628012. The cubic root of 21542964 is about 278.2499864785.

The spelling of 21542964 in words is "twenty-one million, five hundred forty-two thousand, nine hundred sixty-four".