71257631 has 4 divisors (see below), whose sum is σ = 72995664. Its totient is φ = 69519600.

The previous prime is 71257607. The next prime is 71257633. The reversal of 71257631 is 13675217.

71257631 = 411² + 412² + ... + 656².

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

It is not a de Polignac number, because 71257631 - 2¹⁰ = 71256607 is a prime.

It is a super-2 number, since 2×71257631² = 10155299951464322, 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 (71257633) 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, 868955 + ... + 869036.

It is an arithmetic number, because the mean of its divisors is an integer number (18248916).

Almost surely, 2^71257631 is an apocalyptic number.

71257631 is a deficient number, since it is larger than the sum of its proper divisors (1738033).

71257631 is a wasteful number, since it uses less digits than its factorization.

71257631 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1738032.

The product of its digits is 8820, while the sum is 32.

The square root of 71257631 is about 8441.4235173933. The cubic root of 71257631 is about 414.5820168562.

The spelling of 71257631 in words is "seventy-one million, two hundred fifty-seven thousand, six hundred thirty-one".