2261618649 has 12 divisors (see below), whose sum is σ = 3267790500. Its totient is φ = 1507280544.

The previous prime is 2261618629. The next prime is 2261618687. The reversal of 2261618649 is 9468161622.

2261618649 is a `hidden beast` number, since 2 + 26 + 1 + 618 + 6 + 4 + 9 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 1880783424 + 380835225 = 43368^2 + 19515^2 .

It is not a de Polignac number, because 2261618649 - 2⁵ = 2261618617 is a prime.

It is a super-2 number, since 2×2261618649² = 10229837827009170402, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (2261618629) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 6574 + ... + 67575.

It is an arithmetic number, because the mean of its divisors is an integer number (272315875).

Almost surely, 2^2261618649 is an apocalyptic number.

It is an amenable number.

2261618649 is a deficient number, since it is larger than the sum of its proper divisors (1006171851).

2261618649 is a wasteful number, since it uses less digits than its factorization.

2261618649 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 77544 (or 77541 counting only the distinct ones).

The product of its digits is 248832, while the sum is 45.

The square root of 2261618649 is about 47556.4785176531. The cubic root of 2261618649 is about 1312.6223424460.

The spelling of 2261618649 in words is "two billion, two hundred sixty-one million, six hundred eighteen thousand, six hundred forty-nine".