21085670 has 16 divisors (see below), whose sum is σ = 38233728. Its totient is φ = 8372160.

The previous prime is 21085643. The next prime is 21085703. The reversal of 21085670 is 7658012.

It is a congruent number.

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, 6326 + ... + 9065.

It is an arithmetic number, because the mean of its divisors is an integer number (2389608).

Almost surely, 2^21085670 is an apocalyptic number.

21085670 is a deficient number, since it is larger than the sum of its proper divisors (17148058).

21085670 is a wasteful number, since it uses less digits than its factorization.

21085670 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15535.

The product of its (nonzero) digits is 3360, while the sum is 29.

The square root of 21085670 is about 4591.9135444823. The cubic root of 21085670 is about 276.2670785153.

The spelling of 21085670 in words is "twenty-one million, eighty-five thousand, six hundred seventy".