25326490644 has 540 divisors, whose sum is σ = 86179366812. Its totient is φ = 6427330560.

The previous prime is 25326490619. The next prime is 25326490649. The reversal of 25326490644 is 44609462352.

It can be written as a sum of positive squares in 6 ways, for example, as 11148825744 + 14177664900 = 105588^2 + 119070^2 .

It is a super-2 number, since 2×25326490644² (a number of 22 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 25326490644.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (25326490649) by changing a digit.

It is a polite number, since it can be written in 179 ways as a sum of consecutive naturals, for example, 346938192 + ... + 346938264.

Almost surely, 2^25326490644 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 25326490644, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (43089683406).

25326490644 is an abundant number, since it is smaller than the sum of its proper divisors (60852876168).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

25326490644 is a wasteful number, since it uses less digits than its factorization.

25326490644 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 198 (or 139 counting only the distinct ones).

The product of its (nonzero) digits is 1244160, while the sum is 45.

The spelling of 25326490644 in words is "twenty-five billion, three hundred twenty-six million, four hundred ninety thousand, six hundred forty-four".