2591888661 has 6 divisors (see below), whose sum is σ = 3743839190. Its totient is φ = 1727925768.

The previous prime is 2591888647. The next prime is 2591888671. The reversal of 2591888661 is 1668881952.

It is a happy number.

2591888661 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 1456872561 + 1135016100 = 38169^2 + 33690^2 .

It is not a de Polignac number, because 2591888661 - 2⁹ = 2591888149 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 2591888598 and 2591888607.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2591888671) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 143993806 + ... + 143993823.

Almost surely, 2^2591888661 is an apocalyptic number.

It is an amenable number.

2591888661 is a deficient number, since it is larger than the sum of its proper divisors (1151950529).

2591888661 is a wasteful number, since it uses less digits than its factorization.

2591888661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 287987635 (or 287987632 counting only the distinct ones).

The product of its digits is 1658880, while the sum is 54.

The square root of 2591888661 is about 50910.5947814401. The cubic root of 2591888661 is about 1373.6374223659.

The spelling of 2591888661 in words is "two billion, five hundred ninety-one million, eight hundred eighty-eight thousand, six hundred sixty-one".