647377138 has 4 divisors (see below), whose sum is σ = 971065710. Its totient is φ = 323688568.

The previous prime is 647377111. The next prime is 647377141. The reversal of 647377138 is 831773746.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 831773746 = 2 ⋅415886873.

It can be written as a sum of positive squares in only one way, i.e., 445083409 + 202293729 = 21097^2 + 14223^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 161844283 + ... + 161844286.

Almost surely, 2^647377138 is an apocalyptic number.

647377138 is a deficient number, since it is larger than the sum of its proper divisors (323688572).

647377138 is a wasteful number, since it uses less digits than its factorization.

647377138 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 323688571.

The product of its digits is 592704, while the sum is 46.

The square root of 647377138 is about 25443.6070163018. The cubic root of 647377138 is about 865.0723932862.

The spelling of 647377138 in words is "six hundred forty-seven million, three hundred seventy-seven thousand, one hundred thirty-eight".