71931057 has 8 divisors (see below), whose sum is σ = 104627040. Its totient is φ = 43594560.

The previous prime is 71931053. The next prime is 71931059. The reversal of 71931057 is 75013917.

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

It is not a de Polignac number, because 71931057 - 2² = 71931053 is a prime.

It is a super-2 number, since 2×71931057² = 10348153922274498, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (33), and also a Moran number because the ratio is a prime number: 2179729 = 71931057 / (7 + 1 + 9 + 3 + 1 + 0 + 5 + 7).

It is not an unprimeable number, because it can be changed into a prime (71931053) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1089832 + ... + 1089897.

It is an arithmetic number, because the mean of its divisors is an integer number (13078380).

Almost surely, 2^71931057 is an apocalyptic number.

It is an amenable number.

71931057 is a deficient number, since it is larger than the sum of its proper divisors (32695983).

71931057 is a wasteful number, since it uses less digits than its factorization.

71931057 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2179743.

The product of its (nonzero) digits is 6615, while the sum is 33.

The square root of 71931057 is about 8481.2178960336. The cubic root of 71931057 is about 415.8839377436.

The spelling of 71931057 in words is "seventy-one million, nine hundred thirty-one thousand, fifty-seven".