25478990197 has 2 divisors, whose sum is σ = 25478990198. Its totient is φ = 25478990196.

The previous prime is 25478990183. The next prime is 25478990213. The reversal of 25478990197 is 79109987452.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 25418243761 + 60746436 = 159431^2 + 7794^2 .

It is a cyclic number.

It is not a de Polignac number, because 25478990197 - 2¹¹ = 25478988149 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (25478990107) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12739495098 + 12739495099.

It is an arithmetic number, because the mean of its divisors is an integer number (12739495099).

Almost surely, 2^25478990197 is an apocalyptic number.

It is an amenable number.

25478990197 is a deficient number, since it is larger than the sum of its proper divisors (1).

25478990197 is an equidigital number, since it uses as much as digits as its factorization.

25478990197 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 11430720, while the sum is 61.

The spelling of 25478990197 in words is "twenty-five billion, four hundred seventy-eight million, nine hundred ninety thousand, one hundred ninety-seven".