71988457 has 6 divisors (see below), whose sum is σ = 72718574. Its totient is φ = 71265600.

The previous prime is 71988409. The next prime is 71988467. The reversal of 71988457 is 75488917.

It can be written as a sum of positive squares in 3 ways, for example, as 68823616 + 3164841 = 8296^2 + 1779^2 .

It is a de Polignac number, because none of the positive numbers 2^k-71988457 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 71988457.

It is not an unprimeable number, because it can be changed into a prime (71988467) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 6673 + ... + 13729.

Almost surely, 2^71988457 is an apocalyptic number.

It is an amenable number.

71988457 is a deficient number, since it is larger than the sum of its proper divisors (730117).

71988457 is an equidigital number, since it uses as much as digits as its factorization.

71988457 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7259 (or 7158 counting only the distinct ones).

The product of its digits is 564480, while the sum is 49.

The square root of 71988457 is about 8484.6011691770. The cubic root of 71988457 is about 415.9945315633.

The spelling of 71988457 in words is "seventy-one million, nine hundred eighty-eight thousand, four hundred fifty-seven".