25919357661 has 24 divisors (see below), whose sum is σ = 39693108000. Its totient is φ = 16252335072.

The previous prime is 25919357617. The next prime is 25919357669. The reversal of 25919357661 is 16675391952.

25919357661 is a `hidden beast` number, since 2 + 5 + 9 + 1 + 9 + 3 + 576 + 61 = 666.

It is not a de Polignac number, because 25919357661 - 2⁷ = 25919357533 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 25919357598 and 25919357607.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (25919357669) 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, 521466 + ... + 569003.

It is an arithmetic number, because the mean of its divisors is an integer number (1653879500).

Almost surely, 2^25919357661 is an apocalyptic number.

It is an amenable number.

25919357661 is a deficient number, since it is larger than the sum of its proper divisors (13773750339).

25919357661 is a wasteful number, since it uses less digits than its factorization.

25919357661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1090633 (or 1090630 counting only the distinct ones).

The product of its digits is 3061800, while the sum is 54.

The spelling of 25919357661 in words is "twenty-five billion, nine hundred nineteen million, three hundred fifty-seven thousand, six hundred sixty-one".