1561440511 has 2 divisors, whose sum is σ = 1561440512. Its totient is φ = 1561440510.

The previous prime is 1561440493. The next prime is 1561440541. The reversal of 1561440511 is 1150441651.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1561440511 - 2⁵ = 1561440479 is a prime.

It is a super-2 number, since 2×1561440511² = 4876192938783882242, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 1561440511.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1561440541) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 780720255 + 780720256.

It is an arithmetic number, because the mean of its divisors is an integer number (780720256).

Almost surely, 2^1561440511 is an apocalyptic number.

1561440511 is a deficient number, since it is larger than the sum of its proper divisors (1).

1561440511 is an equidigital number, since it uses as much as digits as its factorization.

1561440511 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2400, while the sum is 28.

The square root of 1561440511 is about 39515.0668859361. The cubic root of 1561440511 is about 1160.1348711097.

The spelling of 1561440511 in words is "one billion, five hundred sixty-one million, four hundred forty thousand, five hundred eleven".