21064418 has 8 divisors (see below), whose sum is σ = 31771740. Its totient is φ = 10473840.

The previous prime is 21064363. The next prime is 21064471. The reversal of 21064418 is 81446012.

It can be written as a sum of positive squares in 2 ways, for example, as 14799409 + 6265009 = 3847^2 + 2503^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 28733 + ... + 29456.

Almost surely, 2^21064418 is an apocalyptic number.

21064418 is a deficient number, since it is larger than the sum of its proper divisors (10707322).

21064418 is a wasteful number, since it uses less digits than its factorization.

21064418 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 58372.

The product of its (nonzero) digits is 1536, while the sum is 26.

The square root of 21064418 is about 4589.5988931496. The cubic root of 21064418 is about 276.1742318636.

The spelling of 21064418 in words is "twenty-one million, sixty-four thousand, four hundred eighteen".