17993807881 has 9 divisors (see below), whose sum is σ = 20932664781. Its totient is φ = 15422459052.

The previous prime is 17993807873. The next prime is 17993807987. The reversal of 17993807881 is 18870839971.

The square root of 17993807881 is 134141.

It is a perfect power (a square), and thus also a powerful number.

It is not a de Polignac number, because 17993807881 - 2³ = 17993807873 is a prime.

It is a super-2 number, since 2×17993807881² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (17993807081) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 929406 + ... + 948568.

Almost surely, 2^17993807881 is an apocalyptic number.

17993807881 is the 134141-st square number.

17993807881 is the 67071-st centered octagonal number.

It is an amenable number.

17993807881 is a deficient number, since it is larger than the sum of its proper divisors (2938856900).

17993807881 is an frugal number, since it uses more digits than its factorization.

17993807881 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 38340 (or 19170 counting only the distinct ones).

The product of its (nonzero) digits is 6096384, while the sum is 61.

The spelling of 17993807881 in words is "seventeen billion, nine hundred ninety-three million, eight hundred seven thousand, eight hundred eighty-one".