72171791 has 8 divisors (see below), whose sum is σ = 73700640. Its totient is φ = 70659072.

The previous prime is 72171773. The next prime is 72171829. The reversal of 72171791 is 19717127.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 72171791 - 2²² = 67977487 is a prime.

It is a super-2 number, since 2×72171791² = 10417534832295362, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (72171721) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5231 + ... + 13103.

It is an arithmetic number, because the mean of its divisors is an integer number (9212580).

Almost surely, 2^72171791 is an apocalyptic number.

72171791 is a deficient number, since it is larger than the sum of its proper divisors (1528849).

72171791 is a wasteful number, since it uses less digits than its factorization.

72171791 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8065.

The product of its digits is 6174, while the sum is 35.

The square root of 72171791 is about 8495.3982249215. The cubic root of 72171791 is about 416.3473718823.

The spelling of 72171791 in words is "seventy-two million, one hundred seventy-one thousand, seven hundred ninety-one".