21965118 has 32 divisors (see below), whose sum is σ = 50512896. Its totient is φ = 6237408.

The previous prime is 21965117. The next prime is 21965149. The reversal of 21965118 is 81156912.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21965113) 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, 5755 + ... + 8777.

It is an arithmetic number, because the mean of its divisors is an integer number (1578528).

Almost surely, 2^21965118 is an apocalyptic number.

21965118 is an abundant number, since it is smaller than the sum of its proper divisors (28547778).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21965118 is a wasteful number, since it uses less digits than its factorization.

21965118 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3208.

The product of its digits is 4320, while the sum is 33.

The square root of 21965118 is about 4686.6958510234. The cubic root of 21965118 is about 280.0557627035.

The spelling of 21965118 in words is "twenty-one million, nine hundred sixty-five thousand, one hundred eighteen".