18699391079 has 4 divisors (see below), whose sum is σ = 18766898184. Its totient is φ = 18631883976.

The previous prime is 18699391057. The next prime is 18699391157. The reversal of 18699391079 is 97019399681.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 97019399681 = 4919 ⋅19723399.

It is a cyclic number.

It is not a de Polignac number, because 18699391079 - 2¹² = 18699386983 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18699391279) 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, 33753137 + ... + 33753690.

It is an arithmetic number, because the mean of its divisors is an integer number (4691724546).

Almost surely, 2^18699391079 is an apocalyptic number.

18699391079 is a deficient number, since it is larger than the sum of its proper divisors (67507105).

18699391079 is an equidigital number, since it uses as much as digits as its factorization.

18699391079 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 67507104.

The product of its (nonzero) digits is 6613488, while the sum is 62.

The spelling of 18699391079 in words is "eighteen billion, six hundred ninety-nine million, three hundred ninety-one thousand, seventy-nine".