25518489701 has 2 divisors, whose sum is σ = 25518489702. Its totient is φ = 25518489700.

The previous prime is 25518489691. The next prime is 25518489713. The reversal of 25518489701 is 10798481552.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 25471840801 + 46648900 = 159599^2 + 6830^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-25518489701 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 25518489701.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (25518489721) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12759244850 + 12759244851.

It is an arithmetic number, because the mean of its divisors is an integer number (12759244851).

Almost surely, 2^25518489701 is an apocalyptic number.

It is an amenable number.

25518489701 is a deficient number, since it is larger than the sum of its proper divisors (1).

25518489701 is an equidigital number, since it uses as much as digits as its factorization.

25518489701 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 806400, while the sum is 50.

The spelling of 25518489701 in words is "twenty-five billion, five hundred eighteen million, four hundred eighty-nine thousand, seven hundred one".