21964927 has 4 divisors (see below), whose sum is σ = 22043376. Its totient is φ = 21886480.

The previous prime is 21964903. The next prime is 21964937. The reversal of 21964927 is 72946912.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21964927 is a prime.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21964927.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21964937) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 38803 + ... + 39364.

It is an arithmetic number, because the mean of its divisors is an integer number (5510844).

Almost surely, 2^21964927 is an apocalyptic number.

21964927 is a deficient number, since it is larger than the sum of its proper divisors (78449).

21964927 is an equidigital number, since it uses as much as digits as its factorization.

21964927 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 78448.

The product of its digits is 54432, while the sum is 40.

The square root of 21964927 is about 4686.6754741501. The cubic root of 21964927 is about 280.0549509497.

The spelling of 21964927 in words is "twenty-one million, nine hundred sixty-four thousand, nine hundred twenty-seven".