1561051505 has 24 divisors (see below), whose sum is σ = 2031136632. Its totient is φ = 1144945152.

The previous prime is 1561051493. The next prime is 1561051519. The reversal of 1561051505 is 5051501651.

It is a happy number.

It can be written as a sum of positive squares in 12 ways, for example, as 1498309264 + 62742241 = 38708^2 + 7921^2 .

It is not a de Polignac number, because 1561051505 - 2⁸ = 1561051249 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 4987229 + ... + 4987541.

It is an arithmetic number, because the mean of its divisors is an integer number (84630693).

Almost surely, 2^1561051505 is an apocalyptic number.

It is an amenable number.

1561051505 is a deficient number, since it is larger than the sum of its proper divisors (470085127).

1561051505 is an equidigital number, since it uses as much as digits as its factorization.

1561051505 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 885 (or 608 counting only the distinct ones).

The product of its (nonzero) digits is 3750, while the sum is 29.

The square root of 1561051505 is about 39510.1443302856. The cubic root of 1561051505 is about 1160.0385205698.

The spelling of 1561051505 in words is "one billion, five hundred sixty-one million, fifty-one thousand, five hundred five".