18378953761 has 27 divisors (see below), whose sum is σ = 21701168307. Its totient is φ = 15519939120.

The previous prime is 18378953741. The next prime is 18378953773. The reversal of 18378953761 is 16735987381.

The square root of 18378953761 is 135569.

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., 202521361 + 18176432400 = 14231^2 + 134820^2 .

It is a de Polignac number, because none of the positive numbers 2^k-18378953761 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 18378953696 and 18378953705.

It is not an unprimeable number, because it can be changed into a prime (18378953741) 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, 101541091 + ... + 101541271.

Almost surely, 2^18378953761 is an apocalyptic number.

18378953761 is the 135569-th square number.

18378953761 is the 67785-th centered octagonal number.

It is an amenable number.

18378953761 is a deficient number, since it is larger than the sum of its proper divisors (3322214546).

18378953761 is an frugal number, since it uses more digits than its factorization.

18378953761 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 590 (or 295 counting only the distinct ones).

The product of its digits is 7620480, while the sum is 58.

It can be divided in two parts, 1837 and 8953761, that added together give a palindrome (8955598).

The spelling of 18378953761 in words is "eighteen billion, three hundred seventy-eight million, nine hundred fifty-three thousand, seven hundred sixty-one".