181994724 has 36 divisors (see below), whose sum is σ = 487105164. Its totient is φ = 57096192.

The previous prime is 181994719. The next prime is 181994731. The reversal of 181994724 is 427499181.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 136188900 + 45805824 = 11670^2 + 6768^2 .

It is a tau number, because it is divible by the number of its divisors (36).

It is a self number, because there is not a number n which added to its sum of digits gives 181994724.

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, 148077 + ... + 149300.

It is an arithmetic number, because the mean of its divisors is an integer number (13530699).

Almost surely, 2^181994724 is an apocalyptic number.

It is an amenable number.

181994724 is an abundant number, since it is smaller than the sum of its proper divisors (305110440).

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

181994724 is a wasteful number, since it uses less digits than its factorization.

181994724 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 297404 (or 297399 counting only the distinct ones).

The product of its digits is 145152, while the sum is 45.

The square root of 181994724 is about 13490.5420202451. The cubic root of 181994724 is about 566.6996346832.

The spelling of 181994724 in words is "one hundred eighty-one million, nine hundred ninety-four thousand, seven hundred twenty-four".