17990631918 has 24 divisors (see below), whose sum is σ = 44548231728. Its totient is φ = 5140180512.

The previous prime is 17990631899. The next prime is 17990631937. The reversal of 17990631918 is 81913609971.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (17990631899) and next prime (17990631937).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 71391271 + ... + 71391522.

It is an arithmetic number, because the mean of its divisors is an integer number (1856176322).

Almost surely, 2^17990631918 is an apocalyptic number.

17990631918 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

17990631918 is an abundant number, since it is smaller than the sum of its proper divisors (26557599810).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

17990631918 is a wasteful number, since it uses less digits than its factorization.

17990631918 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 142782808 (or 142782805 counting only the distinct ones).

The product of its (nonzero) digits is 734832, while the sum is 54.

The spelling of 17990631918 in words is "seventeen billion, nine hundred ninety million, six hundred thirty-one thousand, nine hundred eighteen".