25138556785 has 4 divisors (see below), whose sum is σ = 30166268148. Its totient is φ = 20110845424.

The previous prime is 25138556783. The next prime is 25138556789. The reversal of 25138556785 is 58765583152.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 4018038544 + 21120518241 = 63388^2 + 145329^2 .

It is a cyclic number.

It is not a de Polignac number, because 25138556785 - 2¹ = 25138556783 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (25138556783) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2513855674 + ... + 2513855683.

It is an arithmetic number, because the mean of its divisors is an integer number (7541567037).

Almost surely, 2^25138556785 is an apocalyptic number.

It is an amenable number.

25138556785 is a deficient number, since it is larger than the sum of its proper divisors (5027711363).

25138556785 is an equidigital number, since it uses as much as digits as its factorization.

25138556785 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5027711362.

The product of its digits is 10080000, while the sum is 55.

The spelling of 25138556785 in words is "twenty-five billion, one hundred thirty-eight million, five hundred fifty-six thousand, seven hundred eighty-five".