18690770557 has 4 divisors (see below), whose sum is σ = 19195926556. Its totient is φ = 18185614560.

The previous prime is 18690770551. The next prime is 18690770587. The reversal of 18690770557 is 75507709681.

It is a happy number.

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 17672777721 + 1017992836 = 132939^2 + 31906^2 .

It is a cyclic number.

It is not a de Polignac number, because 18690770557 - 2⁷ = 18690770429 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 18690770498 and 18690770507.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18690770551) 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, 252577944 + ... + 252578017.

It is an arithmetic number, because the mean of its divisors is an integer number (4798981639).

Almost surely, 2^18690770557 is an apocalyptic number.

It is an amenable number.

18690770557 is a deficient number, since it is larger than the sum of its proper divisors (505155999).

18690770557 is an equidigital number, since it uses as much as digits as its factorization.

18690770557 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 505155998.

The product of its (nonzero) digits is 3704400, while the sum is 55.

The spelling of 18690770557 in words is "eighteen billion, six hundred ninety million, seven hundred seventy thousand, five hundred fifty-seven".