139552921 has 2 divisors, whose sum is σ = 139552922. Its totient is φ = 139552920.

The previous prime is 139552913. The next prime is 139552927. The reversal of 139552921 is 129255931.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 136539225 + 3013696 = 11685^2 + 1736^2 .

It is a cyclic number.

It is not a de Polignac number, because 139552921 - 2³ = 139552913 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (139552927) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 69776460 + 69776461.

It is an arithmetic number, because the mean of its divisors is an integer number (69776461).

Almost surely, 2^139552921 is an apocalyptic number.

It is an amenable number.

139552921 is a deficient number, since it is larger than the sum of its proper divisors (1).

139552921 is an equidigital number, since it uses as much as digits as its factorization.

139552921 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 24300, while the sum is 37.

The square root of 139552921 is about 11813.2519231582. The cubic root of 139552921 is about 518.6960933775.

The spelling of 139552921 in words is "one hundred thirty-nine million, five hundred fifty-two thousand, nine hundred twenty-one".