181398537 has 12 divisors (see below), whose sum is σ = 262225600. Its totient is φ = 120837528.

The previous prime is 181398533. The next prime is 181398559. The reversal of 181398537 is 735893181.

181398537 is a `hidden beast` number, since 1 + 81 + 39 + 8 + 537 = 666.

It is not a de Polignac number, because 181398537 - 2² = 181398533 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 181398492 and 181398501.

It is not an unprimeable number, because it can be changed into a prime (181398533) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 5388 + ... + 19794.

Almost surely, 2^181398537 is an apocalyptic number.

It is an amenable number.

181398537 is a deficient number, since it is larger than the sum of its proper divisors (80827063).

181398537 is a wasteful number, since it uses less digits than its factorization.

181398537 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15812 (or 15809 counting only the distinct ones).

The product of its digits is 181440, while the sum is 45.

The square root of 181398537 is about 13468.4274137703. The cubic root of 181398537 is about 566.0801505111.

The spelling of 181398537 in words is "one hundred eighty-one million, three hundred ninety-eight thousand, five hundred thirty-seven".