72178551 has 6 divisors (see below), whose sum is σ = 104257920. Its totient is φ = 48119028.

The previous prime is 72178537. The next prime is 72178591. The reversal of 72178551 is 15587127.

It is not a de Polignac number, because 72178551 - 2⁶ = 72178487 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (72178591) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 4009911 + ... + 4009928.

It is an arithmetic number, because the mean of its divisors is an integer number (17376320).

Almost surely, 2^72178551 is an apocalyptic number.

72178551 is a deficient number, since it is larger than the sum of its proper divisors (32079369).

72178551 is a wasteful number, since it uses less digits than its factorization.

72178551 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8019845 (or 8019842 counting only the distinct ones).

The product of its digits is 19600, while the sum is 36.

The square root of 72178551 is about 8495.7960780612. The cubic root of 72178551 is about 416.3603705915.

The spelling of 72178551 in words is "seventy-two million, one hundred seventy-eight thousand, five hundred fifty-one".