21965081 has 8 divisors (see below), whose sum is σ = 22963200. Its totient is φ = 20985120.

The previous prime is 21965077. The next prime is 21965101. The reversal of 21965081 is 18056912.

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

It is a cyclic number.

It is not a de Polignac number, because 21965081 - 2² = 21965077 is a prime.

It is a super-2 number, since 2×21965081² = 964929566673122, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21965681) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2036 + ... + 6933.

It is an arithmetic number, because the mean of its divisors is an integer number (2870400).

Almost surely, 2^21965081 is an apocalyptic number.

It is an amenable number.

21965081 is a deficient number, since it is larger than the sum of its proper divisors (998119).

21965081 is an equidigital number, since it uses as much as digits as its factorization.

21965081 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9079.

The product of its (nonzero) digits is 4320, while the sum is 32.

The square root of 21965081 is about 4686.6919036779. The cubic root of 21965081 is about 280.0556054531.

The spelling of 21965081 in words is "twenty-one million, nine hundred sixty-five thousand, eighty-one".