139179981 has 16 divisors (see below), whose sum is σ = 187407360. Its totient is φ = 91874880.

The previous prime is 139179973. The next prime is 139179983. The reversal of 139179981 is 189971931.

It is a happy number.

It is not a de Polignac number, because 139179981 - 2³ = 139179973 is a prime.

It is a super-2 number, since 2×139179981² = 38742134222320722, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 139179981.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (139179983) 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, 167475 + ... + 168303.

It is an arithmetic number, because the mean of its divisors is an integer number (11712960).

Almost surely, 2^139179981 is an apocalyptic number.

It is an amenable number.

139179981 is a deficient number, since it is larger than the sum of its proper divisors (48227379).

139179981 is a wasteful number, since it uses less digits than its factorization.

139179981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1316.

The product of its digits is 122472, while the sum is 48.

The square root of 139179981 is about 11797.4565479174. The cubic root of 139179981 is about 518.2336282089.

The spelling of 139179981 in words is "one hundred thirty-nine million, one hundred seventy-nine thousand, nine hundred eighty-one".