21966965 has 8 divisors (see below), whose sum is σ = 26431488. Its totient is φ = 17526160.

The previous prime is 21966961. The next prime is 21967019. The reversal of 21966965 is 56966912.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21966965 - 2² = 21966961 is a prime.

It is a super-2 number, since 2×21966965² = 965095102622450, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21966961) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3821 + ... + 7650.

It is an arithmetic number, because the mean of its divisors is an integer number (3303936).

Almost surely, 2^21966965 is an apocalyptic number.

It is an amenable number.

21966965 is a deficient number, since it is larger than the sum of its proper divisors (4464523).

21966965 is a wasteful number, since it uses less digits than its factorization.

21966965 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11859.

The product of its digits is 174960, while the sum is 44.

The square root of 21966965 is about 4686.8928940184. The cubic root of 21966965 is about 280.0636122477.

The spelling of 21966965 in words is "twenty-one million, nine hundred sixty-six thousand, nine hundred sixty-five".