25774145921 has 2 divisors, whose sum is σ = 25774145922. Its totient is φ = 25774145920.

The previous prime is 25774145899. The next prime is 25774145923. The reversal of 25774145921 is 12954147752.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16298096896 + 9476049025 = 127664^2 + 97345^2 .

It is a cyclic number.

It is not a de Polignac number, because 25774145921 - 2⁶ = 25774145857 is a prime.

Together with 25774145923, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (25774145923) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12887072960 + 12887072961.

It is an arithmetic number, because the mean of its divisors is an integer number (12887072961).

Almost surely, 2^25774145921 is an apocalyptic number.

It is an amenable number.

25774145921 is a deficient number, since it is larger than the sum of its proper divisors (1).

25774145921 is an equidigital number, since it uses as much as digits as its factorization.

25774145921 is an evil number, because the sum of its binary digits is even.

The product of its digits is 705600, while the sum is 47.

The spelling of 25774145921 in words is "twenty-five billion, seven hundred seventy-four million, one hundred forty-five thousand, nine hundred twenty-one".