21064570 has 32 divisors (see below), whose sum is σ = 39372480. Its totient is φ = 8108160.

The previous prime is 21064567. The next prime is 21064579. The reversal of 21064570 is 7546012.

It is a super-2 number, since 2×21064570² = 887432218569800, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21064579) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 33721 + ... + 34339.

It is an arithmetic number, because the mean of its divisors is an integer number (1230390).

Almost surely, 2^21064570 is an apocalyptic number.

21064570 is a deficient number, since it is larger than the sum of its proper divisors (18307910).

21064570 is a wasteful number, since it uses less digits than its factorization.

21064570 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 750.

The product of its (nonzero) digits is 1680, while the sum is 25.

The square root of 21064570 is about 4589.6154523010. The cubic root of 21064570 is about 276.1748961494.

The spelling of 21064570 in words is "twenty-one million, sixty-four thousand, five hundred seventy".