18550705397 has 4 divisors (see below), whose sum is σ = 21200806176. Its totient is φ = 15900604620.

The previous prime is 18550705387. The next prime is 18550705409. The reversal of 18550705397 is 79350705581.

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.

It is a cyclic number.

It is not a de Polignac number, because 18550705397 - 2²⁶ = 18483596533 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 (18550705367) 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, 1325050379 + ... + 1325050392.

It is an arithmetic number, because the mean of its divisors is an integer number (5300201544).

Almost surely, 2^18550705397 is an apocalyptic number.

It is an amenable number.

18550705397 is a deficient number, since it is larger than the sum of its proper divisors (2650100779).

18550705397 is an equidigital number, since it uses as much as digits as its factorization.

18550705397 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2650100778.

The product of its (nonzero) digits is 1323000, while the sum is 50.

The spelling of 18550705397 in words is "eighteen billion, five hundred fifty million, seven hundred five thousand, three hundred ninety-seven".