689655862138 has 4 divisors (see below), whose sum is σ = 1034483793210. Its totient is φ = 344827931068.

The previous prime is 689655862127. The next prime is 689655862151. The reversal of 689655862138 is 831268556986.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 529033658409 + 160622203729 = 727347^2 + 400777^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 172413965533 + ... + 172413965536.

Almost surely, 2^689655862138 is an apocalyptic number.

689655862138 is a deficient number, since it is larger than the sum of its proper divisors (344827931072).

689655862138 is a wasteful number, since it uses less digits than its factorization.

689655862138 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 344827931071.

The product of its digits is 149299200, while the sum is 67.

The spelling of 689655862138 in words is "six hundred eighty-nine billion, six hundred fifty-five million, eight hundred sixty-two thousand, one hundred thirty-eight".