25617665977 has 2 divisors, whose sum is σ = 25617665978. Its totient is φ = 25617665976.

The previous prime is 25617665947. The next prime is 25617666007. The reversal of 25617665977 is 77956671652.

It is a happy number.

It is a balanced prime because it is at equal distance from previous prime (25617665947) and next prime (25617666007).

It can be written as a sum of positive squares in only one way, i.e., 25135248681 + 482417296 = 158541^2 + 21964^2 .

It is a cyclic number.

It is not a de Polignac number, because 25617665977 - 2⁷ = 25617665849 is a prime.

It is not a weakly prime, because it can be changed into another prime (25617665947) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12808832988 + 12808832989.

It is an arithmetic number, because the mean of its divisors is an integer number (12808832989).

Almost surely, 2^25617665977 is an apocalyptic number.

It is an amenable number.

25617665977 is a deficient number, since it is larger than the sum of its proper divisors (1).

25617665977 is an equidigital number, since it uses as much as digits as its factorization.

25617665977 is an evil number, because the sum of its binary digits is even.

The product of its digits is 33339600, while the sum is 61.

The spelling of 25617665977 in words is "twenty-five billion, six hundred seventeen million, six hundred sixty-five thousand, nine hundred seventy-seven".