25437877921 has 2 divisors, whose sum is σ = 25437877922. Its totient is φ = 25437877920.

The previous prime is 25437877909. The next prime is 25437877981. The reversal of 25437877921 is 12977873452.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 23695984225 + 1741893696 = 153935^2 + 41736^2 .

It is a cyclic number.

It is not a de Polignac number, because 25437877921 - 2⁵ = 25437877889 is a prime.

It is not a weakly prime, because it can be changed into another prime (25437877981) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12718938960 + 12718938961.

It is an arithmetic number, because the mean of its divisors is an integer number (12718938961).

Almost surely, 2^25437877921 is an apocalyptic number.

It is an amenable number.

25437877921 is a deficient number, since it is larger than the sum of its proper divisors (1).

25437877921 is an equidigital number, since it uses as much as digits as its factorization.

25437877921 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 5927040, while the sum is 55.

The spelling of 25437877921 in words is "twenty-five billion, four hundred thirty-seven million, eight hundred seventy-seven thousand, nine hundred twenty-one".