139905181 has 4 divisors (see below), whose sum is σ = 150667132. Its totient is φ = 129143232.

The previous prime is 139905163. The next prime is 139905191. The reversal of 139905181 is 181509931.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 83429956 + 56475225 = 9134^2 + 7515^2 .

It is a cyclic number.

It is not a de Polignac number, because 139905181 - 2⁵ = 139905149 is a prime.

It is a super-2 number, since 2×139905181² = 39146919341285522, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 139905181.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (139905191) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5380956 + ... + 5380981.

It is an arithmetic number, because the mean of its divisors is an integer number (37666783).

Almost surely, 2^139905181 is an apocalyptic number.

It is an amenable number.

139905181 is a deficient number, since it is larger than the sum of its proper divisors (10761951).

139905181 is a wasteful number, since it uses less digits than its factorization.

139905181 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10761950.

The product of its (nonzero) digits is 9720, while the sum is 37.

The square root of 139905181 is about 11828.1520534697. The cubic root of 139905181 is about 519.1321582108.

The spelling of 139905181 in words is "one hundred thirty-nine million, nine hundred five thousand, one hundred eighty-one".