25448404021 has 4 divisors (see below), whose sum is σ = 26069096844. Its totient is φ = 24827711200.

The previous prime is 25448404019. The next prime is 25448404043. The reversal of 25448404021 is 12040484452.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 5521976100 + 19926427921 = 74310^2 + 141161^2 .

It is a cyclic number.

It is not a de Polignac number, because 25448404021 - 2¹ = 25448404019 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (25448404061) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 310346350 + ... + 310346431.

It is an arithmetic number, because the mean of its divisors is an integer number (6517274211).

Almost surely, 2^25448404021 is an apocalyptic number.

It is an amenable number.

25448404021 is a deficient number, since it is larger than the sum of its proper divisors (620692823).

25448404021 is an equidigital number, since it uses as much as digits as its factorization.

25448404021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 620692822.

The product of its (nonzero) digits is 40960, while the sum is 34.

Adding to 25448404021 its reverse (12040484452), we get a palindrome (37488888473).

The spelling of 25448404021 in words is "twenty-five billion, four hundred forty-eight million, four hundred four thousand, twenty-one".