139879961 has 8 divisors (see below), whose sum is σ = 159501384. Its totient is φ = 121524480.

The previous prime is 139879939. The next prime is 139879979. The reversal of 139879961 is 169978931.

It can be written as a sum of positive squares in 4 ways, for example, as 3924361 + 135955600 = 1981^2 + 11660^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 139879961 - 2¹⁸ = 139617817 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (139879921) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 316250 + ... + 316691.

It is an arithmetic number, because the mean of its divisors is an integer number (19937673).

Almost surely, 2^139879961 is an apocalyptic number.

It is an amenable number.

139879961 is a deficient number, since it is larger than the sum of its proper divisors (19621423).

139879961 is a wasteful number, since it uses less digits than its factorization.

139879961 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 632971.

The product of its digits is 734832, while the sum is 53.

The square root of 139879961 is about 11827.0859048203. The cubic root of 139879961 is about 519.1009625593.

The spelling of 139879961 in words is "one hundred thirty-nine million, eight hundred seventy-nine thousand, nine hundred sixty-one".