71881591 has 4 divisors (see below), whose sum is σ = 74200384. Its totient is φ = 69562800.

The previous prime is 71881583. The next prime is 71881609. The reversal of 71881591 is 19518817.

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

It is a cyclic number.

It is not a de Polignac number, because 71881591 - 2³ = 71881583 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (71881501) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1159350 + ... + 1159411.

It is an arithmetic number, because the mean of its divisors is an integer number (18550096).

Almost surely, 2^71881591 is an apocalyptic number.

71881591 is a deficient number, since it is larger than the sum of its proper divisors (2318793).

71881591 is a wasteful number, since it uses less digits than its factorization.

71881591 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2318792.

The product of its digits is 20160, while the sum is 40.

The square root of 71881591 is about 8478.3011859688. The cubic root of 71881591 is about 415.7885833248.

The spelling of 71881591 in words is "seventy-one million, eight hundred eighty-one thousand, five hundred ninety-one".