2177995561 has 27 divisors (see below), whose sum is σ = 2600266071. Its totient is φ = 1818970944.

The previous prime is 2177995549. The next prime is 2177995571. The reversal of 2177995561 is 1655997712.

The square root of 2177995561 is 46669.

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

It can be written as a sum of positive squares in only one way, i.e., 38378025 + 2139617536 = 6195^2 + 46256^2 .

It is not a de Polignac number, because 2177995561 - 2¹⁵ = 2177962793 is a prime.

It is a Smith number, since the sum of its digits (52) coincides with the sum of the digits of its prime factors.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 2177995499 and 2177995508.

It is not an unprimeable number, because it can be changed into a prime (2177995571) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 19274241 + ... + 19274353.

Almost surely, 2^2177995561 is an apocalyptic number.

2177995561 is the 46669-th square number.

2177995561 is the 23335-th centered octagonal number.

It is an amenable number.

2177995561 is a deficient number, since it is larger than the sum of its proper divisors (422270510).

2177995561 is an frugal number, since it uses more digits than its factorization.

2177995561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 358 (or 179 counting only the distinct ones).

The product of its digits is 1190700, while the sum is 52.

The cubic root of 2177995561 is about 1296.2407295623.

The spelling of 2177995561 in words is "two billion, one hundred seventy-seven million, nine hundred ninety-five thousand, five hundred sixty-one".