1561245071 has 2 divisors, whose sum is σ = 1561245072. Its totient is φ = 1561245070.

The previous prime is 1561245053. The next prime is 1561245121. The reversal of 1561245071 is 1705421651.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1561245071 - 2²⁶ = 1494136207 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1561245871) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 780622535 + 780622536.

It is an arithmetic number, because the mean of its divisors is an integer number (780622536).

Almost surely, 2^1561245071 is an apocalyptic number.

1561245071 is a deficient number, since it is larger than the sum of its proper divisors (1).

1561245071 is an equidigital number, since it uses as much as digits as its factorization.

1561245071 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 8400, while the sum is 32.

The square root of 1561245071 is about 39512.5938277912. The cubic root of 1561245071 is about 1160.0864657604.

The spelling of 1561245071 in words is "one billion, five hundred sixty-one million, two hundred forty-five thousand, seventy-one".