139783121561 has 2 divisors, whose sum is σ = 139783121562. Its totient is φ = 139783121560.

The previous prime is 139783121509. The next prime is 139783121593. The reversal of 139783121561 is 165121387931.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 77704907536 + 62078214025 = 278756^2 + 249155^2 .

It is a cyclic number.

It is not a de Polignac number, because 139783121561 - 2¹⁰ = 139783120537 is a prime.

It is not a weakly prime, because it can be changed into another prime (139783621561) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 69891560780 + 69891560781.

It is an arithmetic number, because the mean of its divisors is an integer number (69891560781).

Almost surely, 2^139783121561 is an apocalyptic number.

It is an amenable number.

139783121561 is a deficient number, since it is larger than the sum of its proper divisors (1).

139783121561 is an equidigital number, since it uses as much as digits as its factorization.

139783121561 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 272160, while the sum is 47.

The spelling of 139783121561 in words is "one hundred thirty-nine billion, seven hundred eighty-three million, one hundred twenty-one thousand, five hundred sixty-one".