25640221231 has 2 divisors, whose sum is σ = 25640221232. Its totient is φ = 25640221230.

The previous prime is 25640221207. The next prime is 25640221237. The reversal of 25640221231 is 13212204652.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 25640221231 - 2¹¹ = 25640219183 is a prime.

It is a super-3 number, since 3×25640221231³ (a number of 32 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a self number, because there is not a number n which added to its sum of digits gives 25640221231.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (25640221237) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12820110615 + 12820110616.

It is an arithmetic number, because the mean of its divisors is an integer number (12820110616).

Almost surely, 2^25640221231 is an apocalyptic number.

25640221231 is a deficient number, since it is larger than the sum of its proper divisors (1).

25640221231 is an equidigital number, since it uses as much as digits as its factorization.

25640221231 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5760, while the sum is 28.

Adding to 25640221231 its reverse (13212204652), we get a palindrome (38852425883).

The spelling of 25640221231 in words is "twenty-five billion, six hundred forty million, two hundred twenty-one thousand, two hundred thirty-one".