72165945 has 32 divisors (see below), whose sum is σ = 118992384. Its totient is φ = 37324800.

The previous prime is 72165941. The next prime is 72165953. The reversal of 72165945 is 54956127.

72165945 = 198² + 199² + ... + 607².

It is not a de Polignac number, because 72165945 - 2² = 72165941 is a prime.

It is not an unprimeable number, because it can be changed into a prime (72165941) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 166449 + ... + 166881.

It is an arithmetic number, because the mean of its divisors is an integer number (3718512).

Almost surely, 2^72165945 is an apocalyptic number.

It is an amenable number.

72165945 is a deficient number, since it is larger than the sum of its proper divisors (46826439).

72165945 is a wasteful number, since it uses less digits than its factorization.

72165945 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 753.

The product of its digits is 75600, while the sum is 39.

The square root of 72165945 is about 8495.0541493271. The cubic root of 72165945 is about 416.3361300364.

It can be divided in two parts, 721 and 65945, that added together give a palindrome (66666).

The spelling of 72165945 in words is "seventy-two million, one hundred sixty-five thousand, nine hundred forty-five".