18888732977689 has 27 divisors (see below), whose sum is σ = 20284043678847. Its totient is φ = 17586753669648.

The previous prime is 18888732977659. The next prime is 18888732977731. The reversal of 18888732977689 is 98677923788881.

The square root of 18888732977689 is 4346117.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 4802913318025 + 14085819659664 = 2191555^2 + 3753108^2 .

It is not a de Polignac number, because 18888732977689 - 2²³ = 18888724589081 is a prime.

It is a super-3 number, since 3×18888732977689³ (a number of 41 digits) contains 333 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18888732977659) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 4871995219 + ... + 4871999095.

Almost surely, 2^{18888732977689} is an apocalyptic number.

18888732977689 is a gapful number since it is divisible by the number (19) formed by its first and last digit.

18888732977689 is the 4346117-th square number.

18888732977689 is the 2173059-th centered octagonal number.

It is an amenable number.

18888732977689 is a deficient number, since it is larger than the sum of its proper divisors (1395310701158).

18888732977689 is an frugal number, since it uses more digits than its factorization.

18888732977689 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7910 (or 3955 counting only the distinct ones).

The product of its digits is 32774160384, while the sum is 91.

The spelling of 18888732977689 in words is "eighteen trillion, eight hundred eighty-eight billion, seven hundred thirty-two million, nine hundred seventy-seven thousand, six hundred eighty-nine".