18446658381 has 6 divisors (see below), whose sum is σ = 26645173230. Its totient is φ = 12297772248.

The previous prime is 18446658337. The next prime is 18446658389. The reversal of 18446658381 is 18385664481.

18446658381 is a `hidden beast` number, since 18 + 4 + 46 + 6 + 583 + 8 + 1 = 666.

It can be written as a sum of positive squares in only one way, i.e., 17734248900 + 712409481 = 133170^2 + 26691^2 .

It is not a de Polignac number, because 18446658381 - 2⁷ = 18446658253 is a prime.

It is a super-2 number, since 2×18446658381² (a number of 21 digits) contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18446658389) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1024814346 + ... + 1024814363.

It is an arithmetic number, because the mean of its divisors is an integer number (4440862205).

Almost surely, 2^18446658381 is an apocalyptic number.

It is an amenable number.

18446658381 is a deficient number, since it is larger than the sum of its proper divisors (8198514849).

18446658381 is a wasteful number, since it uses less digits than its factorization.

18446658381 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2049628715 (or 2049628712 counting only the distinct ones).

The product of its digits is 4423680, while the sum is 54.

The spelling of 18446658381 in words is "eighteen billion, four hundred forty-six million, six hundred fifty-eight thousand, three hundred eighty-one".