21170064 has 20 divisors (see below), whose sum is σ = 54689456. Its totient is φ = 7056672.

The previous prime is 21170053. The next prime is 21170077. The reversal of 21170064 is 46007112.

It is a hoax number, since the sum of its digits (21) coincides with the sum of the digits of its distinct prime factors.

It is a self number, because there is not a number n which added to its sum of digits gives 21170064.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 220474 + ... + 220569.

Almost surely, 2^21170064 is an apocalyptic number.

21170064 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

21170064 is an abundant number, since it is smaller than the sum of its proper divisors (33519392).

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

21170064 is a wasteful number, since it uses less digits than its factorization.

21170064 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 441054 (or 441048 counting only the distinct ones).

The product of its (nonzero) digits is 336, while the sum is 21.

The square root of 21170064 is about 4601.0937830042. The cubic root of 21170064 is about 276.6351681048.

Adding to 21170064 its reverse (46007112), we get a palindrome (67177176).

The spelling of 21170064 in words is "twenty-one million, one hundred seventy thousand, sixty-four".