72279945 has 20 divisors (see below), whose sum is σ = 129569220. Its totient is φ = 38549088.

The previous prime is 72279929. The next prime is 72279959. The reversal of 72279945 is 54997227.

It can be written as a sum of positive squares in 2 ways, for example, as 8982009 + 63297936 = 2997^2 + 7956^2 .

It is not a de Polignac number, because 72279945 - 2⁴ = 72279929 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a self number, because there is not a number n which added to its sum of digits gives 72279945.

It is an unprimeable number.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 88830 + ... + 89639.

It is an arithmetic number, because the mean of its divisors is an integer number (6478461).

Almost surely, 2^72279945 is an apocalyptic number.

It is an amenable number.

72279945 is a deficient number, since it is larger than the sum of its proper divisors (57289275).

72279945 is a wasteful number, since it uses less digits than its factorization.

72279945 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 178486 (or 178477 counting only the distinct ones).

The product of its digits is 317520, while the sum is 45.

The square root of 72279945 is about 8501.7612881097. The cubic root of 72279945 is about 416.5552423835. Note that the first 3 decimals are identical.

The spelling of 72279945 in words is "seventy-two million, two hundred seventy-nine thousand, nine hundred forty-five".