21596965 has 16 divisors (see below), whose sum is σ = 28562688. Its totient is φ = 15575616.

The previous prime is 21596959. The next prime is 21596969. The reversal of 21596965 is 56969512.

It is a cyclic number.

It is not a de Polignac number, because 21596965 - 2⁷ = 21596837 is a prime.

It is a super-2 number, since 2×21596965² = 932857794422450, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (43).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21596969) by changing a digit.

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 15 ways as a sum of consecutive naturals, for example, 1069 + ... + 6658.

It is an arithmetic number, because the mean of its divisors is an integer number (1785168).

Almost surely, 2^21596965 is an apocalyptic number.

It is an amenable number.

21596965 is a deficient number, since it is larger than the sum of its proper divisors (6965723).

21596965 is a wasteful number, since it uses less digits than its factorization.

21596965 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7788.

The product of its digits is 145800, while the sum is 43.

The square root of 21596965 is about 4647.2534899659. The cubic root of 21596965 is about 278.4822856816.

The spelling of 21596965 in words is "twenty-one million, five hundred ninety-six thousand, nine hundred sixty-five".