25785861447 has 32 divisors (see below), whose sum is σ = 34980397056. Its totient is φ = 16894332000.

The previous prime is 25785861421. The next prime is 25785861481. The reversal of 25785861447 is 74416858752.

It is a de Polignac number, because none of the positive numbers 2^k-25785861447 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (25785861047) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 24534072 + ... + 24535122.

It is an arithmetic number, because the mean of its divisors is an integer number (1093137408).

Almost surely, 2^25785861447 is an apocalyptic number.

25785861447 is a deficient number, since it is larger than the sum of its proper divisors (9194535609).

25785861447 is a wasteful number, since it uses less digits than its factorization.

25785861447 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1731.

The product of its digits is 15052800, while the sum is 57.

The spelling of 25785861447 in words is "twenty-five billion, seven hundred eighty-five million, eight hundred sixty-one thousand, four hundred forty-seven".