72178957 has 4 divisors (see below), whose sum is σ = 76424796. Its totient is φ = 67933120.

The previous prime is 72178949. The next prime is 72178987. The reversal of 72178957 is 75987127.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 75987127 = 17 ⋅4469831.

It can be written as a sum of positive squares in 2 ways, for example, as 30846916 + 41332041 = 5554^2 + 6429^2 .

It is a cyclic number.

It is not a de Polignac number, because 72178957 - 2³ = 72178949 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 (72178927) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2122894 + ... + 2122927.

It is an arithmetic number, because the mean of its divisors is an integer number (19106199).

Almost surely, 2^72178957 is an apocalyptic number.

It is an amenable number.

72178957 is a deficient number, since it is larger than the sum of its proper divisors (4245839).

72178957 is a wasteful number, since it uses less digits than its factorization.

72178957 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4245838.

The product of its digits is 246960, while the sum is 46.

The square root of 72178957 is about 8495.8199721981. The cubic root of 72178957 is about 416.3611512573.

The spelling of 72178957 in words is "seventy-two million, one hundred seventy-eight thousand, nine hundred fifty-seven".