72153991 has 32 divisors (see below), whose sum is σ = 91929600. Its totient is φ = 55123200.

The previous prime is 72153979. The next prime is 72154009. The reversal of 72153991 is 19935127.

It is a cyclic number.

It is not a de Polignac number, because 72153991 - 2⁷ = 72153863 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 72153991.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (72153971) 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, 477766 + ... + 477916.

It is an arithmetic number, because the mean of its divisors is an integer number (2872800).

Almost surely, 2^72153991 is an apocalyptic number.

72153991 is a deficient number, since it is larger than the sum of its proper divisors (19775609).

72153991 is a wasteful number, since it uses less digits than its factorization.

72153991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 319.

The product of its digits is 17010, while the sum is 37.

The square root of 72153991 is about 8494.3505343257. The cubic root of 72153991 is about 416.3131406290.

The spelling of 72153991 in words is "seventy-two million, one hundred fifty-three thousand, nine hundred ninety-one".