139839121 has 2 divisors, whose sum is σ = 139839122. Its totient is φ = 139839120.

The previous prime is 139839101. The next prime is 139839157. The reversal of 139839121 is 121938931.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 117418896 + 22420225 = 10836^2 + 4735^2 .

It is a cyclic number.

It is not a de Polignac number, because 139839121 - 2¹¹ = 139837073 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (139839101) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 69919560 + 69919561.

It is an arithmetic number, because the mean of its divisors is an integer number (69919561).

Almost surely, 2^139839121 is an apocalyptic number.

It is an amenable number.

139839121 is a deficient number, since it is larger than the sum of its proper divisors (1).

139839121 is an equidigital number, since it uses as much as digits as its factorization.

139839121 is an evil number, because the sum of its binary digits is even.

The product of its digits is 11664, while the sum is 37.

The square root of 139839121 is about 11825.3592334440. The cubic root of 139839121 is about 519.0504379363.

It can be divided in two parts, 13983 and 9121, that added together give a square (23104 = 152²).

The spelling of 139839121 in words is "one hundred thirty-nine million, eight hundred thirty-nine thousand, one hundred twenty-one".