71895581 has 4 divisors (see below), whose sum is σ = 71918172. Its totient is φ = 71872992.

The previous prime is 71895569. The next prime is 71895587. The reversal of 71895581 is 18559817.

It is a happy number.

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

It can be written as a sum of positive squares in 2 ways, for example, as 28783225 + 43112356 = 5365^2 + 6566^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-71895581 is a prime.

It is a super-2 number, since 2×71895581² = 10337949134655122, 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 (71895587) 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, 5546 + ... + 13211.

It is an arithmetic number, because the mean of its divisors is an integer number (17979543).

Almost surely, 2^71895581 is an apocalyptic number.

It is an amenable number.

71895581 is a deficient number, since it is larger than the sum of its proper divisors (22591).

71895581 is a wasteful number, since it uses less digits than its factorization.

71895581 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22590.

The product of its digits is 100800, while the sum is 44.

The square root of 71895581 is about 8479.1261931876. The cubic root of 71895581 is about 415.8155559468.

The spelling of 71895581 in words is "seventy-one million, eight hundred ninety-five thousand, five hundred eighty-one".