71731397 has 4 divisors (see below), whose sum is σ = 71841900. Its totient is φ = 71620896.

The previous prime is 71731391. The next prime is 71731417. The reversal of 71731397 is 79313717.

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 11296321 + 60435076 = 3361^2 + 7774^2 .

It is a cyclic number.

It is not a de Polignac number, because 71731397 - 2⁸ = 71731141 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 71731397.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (71731391) 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, 54272 + ... + 55577.

It is an arithmetic number, because the mean of its divisors is an integer number (17960475).

Almost surely, 2^71731397 is an apocalyptic number.

It is an amenable number.

71731397 is a deficient number, since it is larger than the sum of its proper divisors (110503).

71731397 is a wasteful number, since it uses less digits than its factorization.

71731397 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 110502.

The product of its digits is 27783, while the sum is 38.

The square root of 71731397 is about 8469.4390014924. The cubic root of 71731397 is about 415.4987896279.

The spelling of 71731397 in words is "seventy-one million, seven hundred thirty-one thousand, three hundred ninety-seven".