18638646601 has 4 divisors (see below), whose sum is σ = 18689433472. Its totient is φ = 18587859732.

The previous prime is 18638646599. The next prime is 18638646629. The reversal of 18638646601 is 10664683681.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 10664683681 = 4657 ⋅2290033.

It is a cyclic number.

It is not a de Polignac number, because 18638646601 - 2¹ = 18638646599 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18638646661) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 25392885 + ... + 25393618.

It is an arithmetic number, because the mean of its divisors is an integer number (4672358368).

Almost surely, 2^18638646601 is an apocalyptic number.

It is an amenable number.

18638646601 is a deficient number, since it is larger than the sum of its proper divisors (50786871).

18638646601 is an equidigital number, since it uses as much as digits as its factorization.

18638646601 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 50786870.

The product of its (nonzero) digits is 995328, while the sum is 49.

The spelling of 18638646601 in words is "eighteen billion, six hundred thirty-eight million, six hundred forty-six thousand, six hundred one".