71638751428 has 6 divisors (see below), whose sum is σ = 125367815006. Its totient is φ = 35819375712.

The previous prime is 71638751411. The next prime is 71638751447. The reversal of 71638751428 is 82415783617.

It can be written as a sum of positive squares in only one way, i.e., 48491563264 + 23147188164 = 220208^2 + 152142^2 .

It is a super-2 number, since 2×71638751428² (a number of 23 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8954843925 + ... + 8954843932.

Almost surely, 2^71638751428 is an apocalyptic number.

It is an amenable number.

71638751428 is a deficient number, since it is larger than the sum of its proper divisors (53729063578).

71638751428 is a wasteful number, since it uses less digits than its factorization.

71638751428 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17909687861 (or 17909687859 counting only the distinct ones).

The product of its digits is 2257920, while the sum is 52.

The spelling of 71638751428 in words is "seventy-one billion, six hundred thirty-eight million, seven hundred fifty-one thousand, four hundred twenty-eight".