18368651961 has 75 divisors (see below), whose sum is σ = 30998674553. Its totient is φ = 10831637520.

The previous prime is 18368651947. The next prime is 18368652007. The reversal of 18368651961 is 16915686381.

The square root of 18368651961 is 135531.

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

18368651961 is a `hidden beast` number, since 1 + 8 + 3 + 68 + 6 + 519 + 61 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 11453066361 + 6915585600 = 107019^2 + 83160^2 .

It is not a de Polignac number, because 18368651961 - 2²⁷ = 18234434233 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 18368651898 and 18368651907.

It is not an unprimeable number, because it can be changed into a prime (18368651921) by changing a digit.

It is a polite number, since it can be written in 74 ways as a sum of consecutive naturals, for example, 496450035 + ... + 496450071.

Almost surely, 2^18368651961 is an apocalyptic number.

18368651961 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

18368651961 is the 135531-st square number.

18368651961 is the 67766-th centered octagonal number.

It is an amenable number.

18368651961 is a deficient number, since it is larger than the sum of its proper divisors (12630022592).

18368651961 is an frugal number, since it uses more digits than its factorization.

18368651961 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 182 (or 51 counting only the distinct ones).

The product of its digits is 1866240, while the sum is 54.

The spelling of 18368651961 in words is "eighteen billion, three hundred sixty-eight million, six hundred fifty-one thousand, nine hundred sixty-one".