71631391 has 8 divisors (see below), whose sum is σ = 77490560. Its totient is φ = 65822112.

The previous prime is 71631377. The next prime is 71631401. The reversal of 71631391 is 19313617.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 71631391 - 2⁹ = 71630879 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 (71634391) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9456 + ... + 15253.

It is an arithmetic number, because the mean of its divisors is an integer number (9686320).

Almost surely, 2^71631391 is an apocalyptic number.

71631391 is a deficient number, since it is larger than the sum of its proper divisors (5859169).

71631391 is a wasteful number, since it uses less digits than its factorization.

71631391 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24945.

The product of its digits is 3402, while the sum is 31.

The square root of 71631391 is about 8463.5330093289. The cubic root of 71631391 is about 415.3056073810.

The spelling of 71631391 in words is "seventy-one million, six hundred thirty-one thousand, three hundred ninety-one".