21513874 has 16 divisors (see below), whose sum is σ = 34898688. Its totient is φ = 9908032.

The previous prime is 21513859. The next prime is 21513887. The reversal of 21513874 is 47831512.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5134 + ... + 8329.

It is an arithmetic number, because the mean of its divisors is an integer number (2181168).

Almost surely, 2^21513874 is an apocalyptic number.

21513874 is a deficient number, since it is larger than the sum of its proper divisors (13384814).

21513874 is a wasteful number, since it uses less digits than its factorization.

21513874 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13529.

The product of its digits is 6720, while the sum is 31.

The square root of 21513874 is about 4638.3050783665. The cubic root of 21513874 is about 278.1246874381.

The spelling of 21513874 in words is "twenty-one million, five hundred thirteen thousand, eight hundred seventy-four".