18738688553 has 4 divisors (see below), whose sum is σ = 20180126148. Its totient is φ = 17297250960.

The previous prime is 18738688543. The next prime is 18738688567. The reversal of 18738688553 is 35588683781.

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

It can be written as a sum of positive squares in 2 ways, for example, as 12248291584 + 6490396969 = 110672^2 + 80563^2 .

It is a cyclic number.

It is not a de Polignac number, because 18738688553 - 2⁴ = 18738688537 is a prime.

It is a super-2 number, since 2×18738688553² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (18738688543) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 720718778 + ... + 720718803.

It is an arithmetic number, because the mean of its divisors is an integer number (5045031537).

Almost surely, 2^18738688553 is an apocalyptic number.

18738688553 is a gapful number since it is divisible by the number (13) formed by its first and last digit.

It is an amenable number.

18738688553 is a deficient number, since it is larger than the sum of its proper divisors (1441437595).

18738688553 is a wasteful number, since it uses less digits than its factorization.

18738688553 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1441437594.

The product of its digits is 38707200, while the sum is 62.

The spelling of 18738688553 in words is "eighteen billion, seven hundred thirty-eight million, six hundred eighty-eight thousand, five hundred fifty-three".