181988406 has 12 divisors (see below), whose sum is σ = 394308252. Its totient is φ = 60662796.

The previous prime is 181988399. The next prime is 181988413. The reversal of 181988406 is 604889181.

It is an interprime number because it is at equal distance from previous prime (181988399) and next prime (181988413).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 5055216 + ... + 5055251.

It is an arithmetic number, because the mean of its divisors is an integer number (32859021).

Almost surely, 2^181988406 is an apocalyptic number.

181988406 is an abundant number, since it is smaller than the sum of its proper divisors (212319846).

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

181988406 is a wasteful number, since it uses less digits than its factorization.

181988406 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10110475 (or 10110472 counting only the distinct ones).

The product of its (nonzero) digits is 110592, while the sum is 45.

The square root of 181988406 is about 13490.3078541596. The cubic root of 181988406 is about 566.6930768929.

The spelling of 181988406 in words is "one hundred eighty-one million, nine hundred eighty-eight thousand, four hundred six".