1561014391 has 2 divisors, whose sum is σ = 1561014392. Its totient is φ = 1561014390.

The previous prime is 1561014379. The next prime is 1561014401. The reversal of 1561014391 is 1934101651.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1561014391 - 2⁹ = 1561013879 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1561014311) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 780507195 + 780507196.

It is an arithmetic number, because the mean of its divisors is an integer number (780507196).

Almost surely, 2^1561014391 is an apocalyptic number.

1561014391 is a deficient number, since it is larger than the sum of its proper divisors (1).

1561014391 is an equidigital number, since it uses as much as digits as its factorization.

1561014391 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3240, while the sum is 31.

The square root of 1561014391 is about 39509.6746506473. The cubic root of 1561014391 is about 1160.0293271916.

The spelling of 1561014391 in words is "one billion, five hundred sixty-one million, fourteen thousand, three hundred ninety-one".