72881665 has 8 divisors (see below), whose sum is σ = 87572520. Its totient is φ = 58228992.

The previous prime is 72881647. The next prime is 72881681. The reversal of 72881665 is 56618827.

It can be written as a sum of positive squares in 4 ways, for example, as 26532801 + 46348864 = 5151^2 + 6808^2 .

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 72881665 - 2²¹ = 70784513 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5160 + ... + 13129.

It is an arithmetic number, because the mean of its divisors is an integer number (10946565).

Almost surely, 2^72881665 is an apocalyptic number.

It is an amenable number.

72881665 is a deficient number, since it is larger than the sum of its proper divisors (14690855).

72881665 is a wasteful number, since it uses less digits than its factorization.

72881665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19091.

The product of its digits is 161280, while the sum is 43.

The square root of 72881665 is about 8537.0759045472. The cubic root of 72881665 is about 417.7079700593.

The spelling of 72881665 in words is "seventy-two million, eight hundred eighty-one thousand, six hundred sixty-five".