139126921 has 2 divisors, whose sum is σ = 139126922. Its totient is φ = 139126920.

The previous prime is 139126901. The next prime is 139126927. The reversal of 139126921 is 129621931.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 134444025 + 4682896 = 11595^2 + 2164^2 .

It is a cyclic number.

It is not a de Polignac number, because 139126921 - 2⁹ = 139126409 is a prime.

It is not a weakly prime, because it can be changed into another prime (139126927) 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, 69563460 + 69563461.

It is an arithmetic number, because the mean of its divisors is an integer number (69563461).

Almost surely, 2^139126921 is an apocalyptic number.

It is an amenable number.

139126921 is a deficient number, since it is larger than the sum of its proper divisors (1).

139126921 is an equidigital number, since it uses as much as digits as its factorization.

139126921 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 5832, while the sum is 34.

The square root of 139126921 is about 11795.2075437442. The cubic root of 139126921 is about 518.1677639202.

The spelling of 139126921 in words is "one hundred thirty-nine million, one hundred twenty-six thousand, nine hundred twenty-one".