21364775 has 12 divisors (see below), whose sum is σ = 26752752. Its totient is φ = 16923840.

The previous prime is 21364771. The next prime is 21364807. The reversal of 21364775 is 57746312.

It is not a de Polignac number, because 21364775 - 2² = 21364771 is a prime.

It is a super-2 number, since 2×21364775² = 912907221601250, which contains 22 as substring.

It is a hoax number, since the sum of its digits (35) coincides with the sum of the digits of its distinct prime factors.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21364771) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1574 + ... + 6723.

It is an arithmetic number, because the mean of its divisors is an integer number (2229396).

Almost surely, 2^21364775 is an apocalyptic number.

21364775 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

21364775 is a deficient number, since it is larger than the sum of its proper divisors (5387977).

21364775 is a wasteful number, since it uses less digits than its factorization.

21364775 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8410 (or 8405 counting only the distinct ones).

The product of its digits is 35280, while the sum is 35.

The square root of 21364775 is about 4622.2045605966. The cubic root of 21364775 is about 277.4806955702.

The spelling of 21364775 in words is "twenty-one million, three hundred sixty-four thousand, seven hundred seventy-five".