25421987771 has 2 divisors, whose sum is σ = 25421987772. Its totient is φ = 25421987770.

The previous prime is 25421987753. The next prime is 25421987819. The reversal of 25421987771 is 17778912452.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 25421987771 - 2¹⁰ = 25421986747 is a prime.

It is a Sophie Germain prime.

It is not a weakly prime, because it can be changed into another prime (25421987671) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12710993885 + 12710993886.

It is an arithmetic number, because the mean of its divisors is an integer number (12710993886).

Almost surely, 2^25421987771 is an apocalyptic number.

25421987771 is a deficient number, since it is larger than the sum of its proper divisors (1).

25421987771 is an equidigital number, since it uses as much as digits as its factorization.

25421987771 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1975680, while the sum is 53.

The spelling of 25421987771 in words is "twenty-five billion, four hundred twenty-one million, nine hundred eighty-seven thousand, seven hundred seventy-one".