72909965 has 4 divisors (see below), whose sum is σ = 87491964. Its totient is φ = 58327968.

The previous prime is 72909961. The next prime is 72909997. The reversal of 72909965 is 56990927.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 34445161 + 38464804 = 5869^2 + 6202^2 .

It is a cyclic number.

It is not a de Polignac number, because 72909965 - 2² = 72909961 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (72909961) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7290992 + ... + 7291001.

It is an arithmetic number, because the mean of its divisors is an integer number (21872991).

Almost surely, 2^72909965 is an apocalyptic number.

It is an amenable number.

72909965 is a deficient number, since it is larger than the sum of its proper divisors (14581999).

72909965 is a wasteful number, since it uses less digits than its factorization.

72909965 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14581998.

The product of its (nonzero) digits is 306180, while the sum is 47.

The square root of 72909965 is about 8538.7332198635. The cubic root of 72909965 is about 417.7620284924.

The spelling of 72909965 in words is "seventy-two million, nine hundred nine thousand, nine hundred sixty-five".