25406661977 has 2 divisors, whose sum is σ = 25406661978. Its totient is φ = 25406661976.

The previous prime is 25406661953. The next prime is 25406662007. The reversal of 25406661977 is 77916660452.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 24937463056 + 469198921 = 157916^2 + 21661^2 .

It is a cyclic number.

It is not a de Polignac number, because 25406661977 - 2⁶ = 25406661913 is a prime.

It is not a weakly prime, because it can be changed into another prime (25406661377) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12703330988 + 12703330989.

It is an arithmetic number, because the mean of its divisors is an integer number (12703330989).

Almost surely, 2^25406661977 is an apocalyptic number.

It is an amenable number.

25406661977 is a deficient number, since it is larger than the sum of its proper divisors (1).

25406661977 is an equidigital number, since it uses as much as digits as its factorization.

25406661977 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3810240, while the sum is 53.

The spelling of 25406661977 in words is "twenty-five billion, four hundred six million, six hundred sixty-one thousand, nine hundred seventy-seven".