181620990 has 48 divisors (see below), whose sum is σ = 473192928. Its totient is φ = 48331968.

The previous prime is 181620977. The next prime is 181621001. The reversal of 181620990 is 99026181.

181620990 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 48319 + ... + 51941.

It is an arithmetic number, because the mean of its divisors is an integer number (9858186).

Almost surely, 2^181620990 is an apocalyptic number.

181620990 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

181620990 is an abundant number, since it is smaller than the sum of its proper divisors (291571938).

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

181620990 is a wasteful number, since it uses less digits than its factorization.

181620990 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4193 (or 4190 counting only the distinct ones).

The product of its (nonzero) digits is 7776, while the sum is 36.

The square root of 181620990 is about 13476.6831972856. The cubic root of 181620990 is about 566.3114548157.

The spelling of 181620990 in words is "one hundred eighty-one million, six hundred twenty thousand, nine hundred ninety".