21513710 has 32 divisors (see below), whose sum is σ = 39724992. Its totient is φ = 8386560.

The previous prime is 21513697. The next prime is 21513749. The reversal of 21513710 is 1731512.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 111374 + ... + 111566.

It is an arithmetic number, because the mean of its divisors is an integer number (1241406).

Almost surely, 2^21513710 is an apocalyptic number.

21513710 is a deficient number, since it is larger than the sum of its proper divisors (18211282).

21513710 is a wasteful number, since it uses less digits than its factorization.

21513710 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 428.

The product of its (nonzero) digits is 210, while the sum is 20.

The square root of 21513710 is about 4638.2873994611. The cubic root of 21513710 is about 278.1239807226.

The spelling of 21513710 in words is "twenty-one million, five hundred thirteen thousand, seven hundred ten".