71638657533 has 12 divisors (see below), whose sum is σ = 104233376988. Its totient is φ = 47410497600.

The previous prime is 71638657487. The next prime is 71638657583. The reversal of 71638657533 is 33575683617.

71638657533 is a `hidden beast` number, since 7 + 1 + 6 + 38 + 6 + 575 + 33 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 34249794489 + 37388863044 = 185067^2 + 193362^2 .

It is not a de Polignac number, because 71638657533 - 2¹⁴ = 71638641149 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 71638657533.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (71638657583) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 29049318 + ... + 29051783.

It is an arithmetic number, because the mean of its divisors is an integer number (8686114749).

Almost surely, 2^71638657533 is an apocalyptic number.

It is an amenable number.

71638657533 is a deficient number, since it is larger than the sum of its proper divisors (32594719455).

71638657533 is a wasteful number, since it uses less digits than its factorization.

71638657533 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 58101244 (or 58101241 counting only the distinct ones).

The product of its digits is 9525600, while the sum is 54.

The spelling of 71638657533 in words is "seventy-one billion, six hundred thirty-eight million, six hundred fifty-seven thousand, five hundred thirty-three".