1061561561 has 16 divisors (see below), whose sum is σ = 1102050768. Its totient is φ = 1021766400.

The previous prime is 1061561533. The next prime is 1061561581. The reversal of 1061561561 is 1651651601.

It can be written as a sum of positive squares in 8 ways, for example, as 13097161 + 1048464400 = 3619^2 + 32380^2 .

It is a cyclic number.

It is not a de Polignac number, because 1061561561 - 2¹⁰ = 1061560537 is a prime.

It is a super-2 number, since 2×1061561561² = 2253825895585513442, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1061561581) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1961951 + ... + 1962491.

It is an arithmetic number, because the mean of its divisors is an integer number (68878173).

Almost surely, 2^1061561561 is an apocalyptic number.

It is an amenable number.

1061561561 is a deficient number, since it is larger than the sum of its proper divisors (40489207).

1061561561 is a wasteful number, since it uses less digits than its factorization.

1061561561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1052.

The product of its (nonzero) digits is 5400, while the sum is 32.

The square root of 1061561561 is about 32581.6138489179. The cubic root of 1061561561 is about 1020.1132646873.

The spelling of 1061561561 in words is "one billion, sixty-one million, five hundred sixty-one thousand, five hundred sixty-one".