1561065139 has 2 divisors, whose sum is σ = 1561065140. Its totient is φ = 1561065138.

The previous prime is 1561065083. The next prime is 1561065197. The reversal of 1561065139 is 9315601651.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1561065139 - 2²¹ = 1558967987 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1561065098 and 1561065107.

It is not a weakly prime, because it can be changed into another prime (1561065199) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 780532569 + 780532570.

It is an arithmetic number, because the mean of its divisors is an integer number (780532570).

Almost surely, 2^1561065139 is an apocalyptic number.

1561065139 is a deficient number, since it is larger than the sum of its proper divisors (1).

1561065139 is an equidigital number, since it uses as much as digits as its factorization.

1561065139 is an odious number, because the sum of its binary digits is odd.

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

The square root of 1561065139 is about 39510.3168678764. The cubic root of 1561065139 is about 1160.0418977633.

The spelling of 1561065139 in words is "one billion, five hundred sixty-one million, sixty-five thousand, one hundred thirty-nine".