18735965231 has 4 divisors (see below), whose sum is σ = 19043112264. Its totient is φ = 18428818200.

The previous prime is 18735965197. The next prime is 18735965233. The reversal of 18735965231 is 13256953781.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 13256953781 = 22901 ⋅578881.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18735965231 is a prime.

It is a super-2 number, since 2×18735965231² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 18735965231.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18735965233) 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, 153573425 + ... + 153573546.

It is an arithmetic number, because the mean of its divisors is an integer number (4760778066).

Almost surely, 2^18735965231 is an apocalyptic number.

18735965231 is a deficient number, since it is larger than the sum of its proper divisors (307147033).

18735965231 is an equidigital number, since it uses as much as digits as its factorization.

18735965231 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 307147032.

The product of its digits is 1360800, while the sum is 50.

The spelling of 18735965231 in words is "eighteen billion, seven hundred thirty-five million, nine hundred sixty-five thousand, two hundred thirty-one".