181940638 has 8 divisors (see below), whose sum is σ = 297721080. Its totient is φ = 82700280.

The previous prime is 181940621. The next prime is 181940651. The reversal of 181940638 is 836049181.

181940638 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a self number, because there is not a number n which added to its sum of digits gives 181940638.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4134993 + ... + 4135036.

It is an arithmetic number, because the mean of its divisors is an integer number (37215135).

Almost surely, 2^181940638 is an apocalyptic number.

181940638 is a deficient number, since it is larger than the sum of its proper divisors (115780442).

181940638 is a wasteful number, since it uses less digits than its factorization.

181940638 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8270042.

The product of its (nonzero) digits is 41472, while the sum is 40.

The square root of 181940638 is about 13488.5372817070. The cubic root of 181940638 is about 566.6434910168.

The spelling of 181940638 in words is "one hundred eighty-one million, nine hundred forty thousand, six hundred thirty-eight".