72115571 has 4 divisors (see below), whose sum is σ = 78671544. Its totient is φ = 65559600.

The previous prime is 72115529. The next prime is 72115591. The reversal of 72115571 is 17551127.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 17551127 = 11 ⋅1595557.

It is a cyclic number.

It is not a de Polignac number, because 72115571 - 2¹⁴ = 72099187 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (72115501) 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, 3277970 + ... + 3277991.

It is an arithmetic number, because the mean of its divisors is an integer number (19667886).

Almost surely, 2^72115571 is an apocalyptic number.

72115571 is a deficient number, since it is larger than the sum of its proper divisors (6555973).

72115571 is a wasteful number, since it uses less digits than its factorization.

72115571 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6555972.

The product of its digits is 2450, while the sum is 29.

The square root of 72115571 is about 8492.0887301064. The cubic root of 72115571 is about 416.2392357745.

Adding to 72115571 its reverse (17551127), we get a palindrome (89666698).

It can be divided in two parts, 721 and 15571, that multiplied together give a triangular number (11226691 = T₄₇₃₈).

The spelling of 72115571 in words is "seventy-two million, one hundred fifteen thousand, five hundred seventy-one".