71631389 has 4 divisors (see below), whose sum is σ = 71865024. Its totient is φ = 71397756.

The previous prime is 71631377. The next prime is 71631401. The reversal of 71631389 is 98313617.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 98313617 = 31 ⋅3171407.

It is an interprime number because it is at equal distance from previous prime (71631377) and next prime (71631401).

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-71631389 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 (71631689) 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, 116357 + ... + 116970.

It is an arithmetic number, because the mean of its divisors is an integer number (17966256).

Almost surely, 2^71631389 is an apocalyptic number.

It is an amenable number.

71631389 is a deficient number, since it is larger than the sum of its proper divisors (233635).

71631389 is a wasteful number, since it uses less digits than its factorization.

71631389 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 233634.

The product of its digits is 27216, while the sum is 38.

The square root of 71631389 is about 8463.5328911749. The cubic root of 71631389 is about 415.3056035158.

The spelling of 71631389 in words is "seventy-one million, six hundred thirty-one thousand, three hundred eighty-nine".