72811571 has 4 divisors (see below), whose sum is σ = 83213232. Its totient is φ = 62409912.

The previous prime is 72811549. The next prime is 72811573. The reversal of 72811571 is 17511827.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-72811571 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (72811573) 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 3 ways as a sum of consecutive naturals, for example, 5200820 + ... + 5200833.

It is an arithmetic number, because the mean of its divisors is an integer number (20803308).

Almost surely, 2^72811571 is an apocalyptic number.

72811571 is a deficient number, since it is larger than the sum of its proper divisors (10401661).

72811571 is a wasteful number, since it uses less digits than its factorization.

72811571 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10401660.

The product of its digits is 3920, while the sum is 32.

The square root of 72811571 is about 8532.9696471979. The cubic root of 72811571 is about 417.5740167814.

The spelling of 72811571 in words is "seventy-two million, eight hundred eleven thousand, five hundred seventy-one".