139012561 has 2 divisors, whose sum is σ = 139012562. Its totient is φ = 139012560.

The previous prime is 139012547. The next prime is 139012567. The reversal of 139012561 is 165210931.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 100881936 + 38130625 = 10044^2 + 6175^2 .

It is a cyclic number.

It is not a de Polignac number, because 139012561 - 2¹⁵ = 138979793 is a prime.

It is not a weakly prime, because it can be changed into another prime (139012567) 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, 69506280 + 69506281.

It is an arithmetic number, because the mean of its divisors is an integer number (69506281).

Almost surely, 2^139012561 is an apocalyptic number.

It is an amenable number.

139012561 is a deficient number, since it is larger than the sum of its proper divisors (1).

139012561 is an equidigital number, since it uses as much as digits as its factorization.

139012561 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1620, while the sum is 28.

The square root of 139012561 is about 11790.3588155747. The cubic root of 139012561 is about 518.0257499262.

The spelling of 139012561 in words is "one hundred thirty-nine million, twelve thousand, five hundred sixty-one".