18631609690 has 16 divisors (see below), whose sum is σ = 33996308328. Its totient is φ = 7350552576.

The previous prime is 18631609679. The next prime is 18631609693. The reversal of 18631609690 is 9690613681.

It can be written as a sum of positive squares in 4 ways, for example, as 18604141609 + 27468081 = 136397^2 + 5241^2 .

It is a super-2 number, since 2×18631609690² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (18631609693) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 12760647 + ... + 12762106.

Almost surely, 2^18631609690 is an apocalyptic number.

18631609690 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

18631609690 is a deficient number, since it is larger than the sum of its proper divisors (15364698638).

18631609690 is a wasteful number, since it uses less digits than its factorization.

18631609690 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25522833.

The product of its (nonzero) digits is 419904, while the sum is 49.

The spelling of 18631609690 in words is "eighteen billion, six hundred thirty-one million, six hundred nine thousand, six hundred ninety".