139668121 has 4 divisors (see below), whose sum is σ = 145740672. Its totient is φ = 133595572.

The previous prime is 139668097. The next prime is 139668127. The reversal of 139668121 is 121866931.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 139668121 - 2¹¹ = 139666073 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (139668127) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3036241 + ... + 3036286.

It is an arithmetic number, because the mean of its divisors is an integer number (36435168).

Almost surely, 2^139668121 is an apocalyptic number.

It is an amenable number.

139668121 is a deficient number, since it is larger than the sum of its proper divisors (6072551).

139668121 is an equidigital number, since it uses as much as digits as its factorization.

139668121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6072550.

The product of its digits is 15552, while the sum is 37.

The square root of 139668121 is about 11818.1267974244. The cubic root of 139668121 is about 518.8387808372.

The spelling of 139668121 in words is "one hundred thirty-nine million, six hundred sixty-eight thousand, one hundred twenty-one".