25513621605 has 12 divisors (see below), whose sum is σ = 44223610860. Its totient is φ = 13607264832.

The previous prime is 25513621597. The next prime is 25513621633. The reversal of 25513621605 is 50612631552.

25513621605 is a `hidden beast` number, since 25 + 5 + 1 + 3 + 6 + 21 + 605 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 15956995041 + 9556626564 = 126321^2 + 97758^2 .

It is not a de Polignac number, because 25513621605 - 2³ = 25513621597 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 25513621605.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 283484640 + ... + 283484729.

It is an arithmetic number, because the mean of its divisors is an integer number (3685300905).

Almost surely, 2^25513621605 is an apocalyptic number.

It is an amenable number.

25513621605 is a deficient number, since it is larger than the sum of its proper divisors (18709989255).

25513621605 is a wasteful number, since it uses less digits than its factorization.

25513621605 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 566969380 (or 566969377 counting only the distinct ones).

The product of its (nonzero) digits is 54000, while the sum is 36.

The spelling of 25513621605 in words is "twenty-five billion, five hundred thirteen million, six hundred twenty-one thousand, six hundred five".