25645961801 has 4 divisors (see below), whose sum is σ = 25818082500. Its totient is φ = 25473841104.

The previous prime is 25645961749. The next prime is 25645961827. The reversal of 25645961801 is 10816954652.

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 5849190400 + 19796771401 = 76480^2 + 140701^2 .

It is a cyclic number.

It is not a de Polignac number, because 25645961801 - 2¹⁰ = 25645960777 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (25645361801) 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, 86060126 + ... + 86060423.

It is an arithmetic number, because the mean of its divisors is an integer number (6454520625).

Almost surely, 2^25645961801 is an apocalyptic number.

It is an amenable number.

25645961801 is a deficient number, since it is larger than the sum of its proper divisors (172120699).

25645961801 is a wasteful number, since it uses less digits than its factorization.

25645961801 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 172120698.

The product of its (nonzero) digits is 518400, while the sum is 47.

The spelling of 25645961801 in words is "twenty-five billion, six hundred forty-five million, nine hundred sixty-one thousand, eight hundred one".