25444352021 has 12 divisors (see below), whose sum is σ = 28932168300. Its totient is φ = 22333597440.

The previous prime is 25444352009. The next prime is 25444352027. The reversal of 25444352021 is 12025344452.

It can be written as a sum of positive squares in 2 ways, for example, as 13465049521 + 11979302500 = 116039^2 + 109450^2 .

It is a de Polignac number, because none of the positive numbers 2^k-25444352021 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 (25444352027) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 3622076 + ... + 3629093.

It is an arithmetic number, because the mean of its divisors is an integer number (2411014025).

Almost surely, 2^25444352021 is an apocalyptic number.

It is an amenable number.

25444352021 is a deficient number, since it is larger than the sum of its proper divisors (3487816279).

25444352021 is a wasteful number, since it uses less digits than its factorization.

25444352021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7251220 (or 7251209 counting only the distinct ones).

The product of its (nonzero) digits is 38400, while the sum is 32.

Adding to 25444352021 its reverse (12025344452), we get a palindrome (37469696473).

The spelling of 25444352021 in words is "twenty-five billion, four hundred forty-four million, three hundred fifty-two thousand, twenty-one".