21064407 has 64 divisors (see below), whose sum is σ = 37847040. Its totient is φ = 10108800.

The previous prime is 21064363. The next prime is 21064471. The reversal of 21064407 is 70446012.

It is not a de Polignac number, because 21064407 - 2¹⁵ = 21031639 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21064607) 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 63 ways as a sum of consecutive naturals, for example, 160732 + ... + 160862.

It is an arithmetic number, because the mean of its divisors is an integer number (591360).

Almost surely, 2^21064407 is an apocalyptic number.

21064407 is a deficient number, since it is larger than the sum of its proper divisors (16782633).

21064407 is a wasteful number, since it uses less digits than its factorization.

21064407 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 204.

The product of its (nonzero) digits is 1344, while the sum is 24.

The square root of 21064407 is about 4589.5976947876. The cubic root of 21064407 is about 276.1741837902.

The spelling of 21064407 in words is "twenty-one million, sixty-four thousand, four hundred seven".