2025815661 has 12 divisors (see below), whose sum is σ = 2981389788. Its totient is φ = 1325061504.

The previous prime is 2025815657. The next prime is 2025815669. The reversal of 2025815661 is 1665185202.

2025815661 is a `hidden beast` number, since 20 + 2 + 581 + 56 + 6 + 1 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 1481480100 + 544335561 = 38490^2 + 23331^2 .

It is not a de Polignac number, because 2025815661 - 2² = 2025815657 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2025815669) 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, 2123020 + ... + 2123973.

It is an arithmetic number, because the mean of its divisors is an integer number (248449149).

Almost surely, 2^2025815661 is an apocalyptic number.

It is an amenable number.

2025815661 is a deficient number, since it is larger than the sum of its proper divisors (955574127).

2025815661 is a wasteful number, since it uses less digits than its factorization.

2025815661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4247052 (or 4247049 counting only the distinct ones).

The product of its (nonzero) digits is 28800, while the sum is 36.

The square root of 2025815661 is about 45009.0619875598. The cubic root of 2025815661 is about 1265.3188406152.

The spelling of 2025815661 in words is "two billion, twenty-five million, eight hundred fifteen thousand, six hundred sixty-one".