21064610 has 24 divisors (see below), whose sum is σ = 44107740. Its totient is φ = 7221984.

The previous prime is 21064607. The next prime is 21064621. The reversal of 21064610 is 1646012.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 20894041 + 170569 = 4571^2 + 413^2 .

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 11 ways as a sum of consecutive naturals, for example, 21005 + ... + 21984.

Almost surely, 2^21064610 is an apocalyptic number.

21064610 is an abundant number, since it is smaller than the sum of its proper divisors (23043130).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21064610 is a wasteful number, since it uses less digits than its factorization.

21064610 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 43010 (or 43003 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 20.

The square root of 21064610 is about 4589.6198099625. The cubic root of 21064610 is about 276.1750709610.

The spelling of 21064610 in words is "twenty-one million, sixty-four thousand, six hundred ten".