139561818 has 32 divisors (see below), whose sum is σ = 304938432. Its totient is φ = 42230400.

The previous prime is 139561813. The next prime is 139561819. The reversal of 139561818 is 818165931.

It is a self number, because there is not a number n which added to its sum of digits gives 139561818.

It is not an unprimeable number, because it can be changed into a prime (139561813) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 69030 + ... + 71022.

It is an arithmetic number, because the mean of its divisors is an integer number (9529326).

Almost surely, 2^139561818 is an apocalyptic number.

139561818 is an abundant number, since it is smaller than the sum of its proper divisors (165376614).

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

139561818 is a wasteful number, since it uses less digits than its factorization.

139561818 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3070.

The product of its digits is 51840, while the sum is 42.

The square root of 139561818 is about 11813.6284857786. The cubic root of 139561818 is about 518.7071160563.

The spelling of 139561818 in words is "one hundred thirty-nine million, five hundred sixty-one thousand, eight hundred eighteen".