1061521561 has 9 divisors (see below), whose sum is σ = 1097913429. Its totient is φ = 1026301500.

The previous prime is 1061521523. The next prime is 1061521567. The reversal of 1061521561 is 1651251601.

It is a happy number.

The square root of 1061521561 is 32581.

It is a perfect power (a square), and thus also a powerful number.

1061521561 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 1061521561 - 2⁹ = 1061521049 is a prime.

It is a super-2 number, since 2×1061521561² = 2253656048935753442, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1061521567) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 1009486 + ... + 1010536.

It is an arithmetic number, because the mean of its divisors is an integer number (121990381).

Almost surely, 2^1061521561 is an apocalyptic number.

1061521561 is the 32581-st square number.

1061521561 is the 16291-st centered octagonal number.

It is an amenable number.

1061521561 is a deficient number, since it is larger than the sum of its proper divisors (36391868).

1061521561 is an frugal number, since it uses more digits than its factorization.

1061521561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2164 (or 1082 counting only the distinct ones).

The product of its (nonzero) digits is 1800, while the sum is 28.

The cubic root of 1061521561 is about 1020.1004517884.

The spelling of 1061521561 in words is "one billion, sixty-one million, five hundred twenty-one thousand, five hundred sixty-one".