2661545161 has 24 divisors (see below), whose sum is σ = 3031732872. Its totient is φ = 2332915200.

The previous prime is 2661545141. The next prime is 2661545191. The reversal of 2661545161 is 1615451662.

It can be written as a sum of positive squares in 4 ways, for example, as 446054400 + 2215490761 = 21120^2 + 47069^2 .

It is not a de Polignac number, because 2661545161 - 2¹⁵ = 2661512393 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (37).

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 2661545161.

It is not an unprimeable number, because it can be changed into a prime (2661545111) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 503271 + ... + 508531.

It is an arithmetic number, because the mean of its divisors is an integer number (126322203).

Almost surely, 2^2661545161 is an apocalyptic number.

It is an amenable number.

2661545161 is a deficient number, since it is larger than the sum of its proper divisors (370187711).

2661545161 is a wasteful number, since it uses less digits than its factorization.

2661545161 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5433 (or 5422 counting only the distinct ones).

The product of its digits is 43200, while the sum is 37.

The square root of 2661545161 is about 51590.1653515474. The cubic root of 2661545161 is about 1385.8342163345.

The spelling of 2661545161 in words is "two billion, six hundred sixty-one million, five hundred forty-five thousand, one hundred sixty-one".