18101461581 has 32 divisors (see below), whose sum is σ = 30689464320. Its totient is φ = 10329690672.

The previous prime is 18101461577. The next prime is 18101461639. The reversal of 18101461581 is 18516410181.

18101461581 is a `hidden beast` number, since 1 + 8 + 1 + 0 + 14 + 61 + 581 = 666.

It is not a de Polignac number, because 18101461581 - 2² = 18101461577 is a prime.

It is a super-2 number, since 2×18101461581² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18101461561) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 75976 + ... + 204878.

It is an arithmetic number, because the mean of its divisors is an integer number (959045760).

Almost surely, 2^18101461581 is an apocalyptic number.

It is an amenable number.

18101461581 is a deficient number, since it is larger than the sum of its proper divisors (12588002739).

18101461581 is a wasteful number, since it uses less digits than its factorization.

18101461581 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 129662 (or 129656 counting only the distinct ones).

The product of its (nonzero) digits is 7680, while the sum is 36.

The spelling of 18101461581 in words is "eighteen billion, one hundred one million, four hundred sixty-one thousand, five hundred eighty-one".