21964965 has 16 divisors (see below), whose sum is σ = 38339136. Its totient is φ = 10649600.

The previous prime is 21964951. The next prime is 21964967. The reversal of 21964965 is 56946912.

It is a happy number.

It is not a de Polignac number, because 21964965 - 2⁷ = 21964837 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21964967) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 66396 + ... + 66725.

It is an arithmetic number, because the mean of its divisors is an integer number (2396196).

Almost surely, 2^21964965 is an apocalyptic number.

It is an amenable number.

21964965 is a deficient number, since it is larger than the sum of its proper divisors (16374171).

21964965 is a wasteful number, since it uses less digits than its factorization.

21964965 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 133140.

The product of its digits is 116640, while the sum is 42.

The square root of 21964965 is about 4686.6795281948. The cubic root of 21964965 is about 280.0551124508.

The spelling of 21964965 in words is "twenty-one million, nine hundred sixty-four thousand, nine hundred sixty-five".