18940815658 has 4 divisors (see below), whose sum is σ = 28411223490. Its totient is φ = 9470407828.

The previous prime is 18940815653. The next prime is 18940815697. The reversal of 18940815658 is 85651804981.

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

It can be written as a sum of positive squares in only one way, i.e., 18931833649 + 8982009 = 137593^2 + 2997^2 .

It is a junction number, because it is equal to n+sod(n) for n = 18940815599 and 18940815608.

It is not an unprimeable number, because it can be changed into a prime (18940815653) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4735203913 + ... + 4735203916.

Almost surely, 2^18940815658 is an apocalyptic number.

18940815658 is a deficient number, since it is larger than the sum of its proper divisors (9470407832).

18940815658 is an equidigital number, since it uses as much as digits as its factorization.

18940815658 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9470407831.

The product of its (nonzero) digits is 2764800, while the sum is 55.

The spelling of 18940815658 in words is "eighteen billion, nine hundred forty million, eight hundred fifteen thousand, six hundred fifty-eight".