25187911849 has 9 divisors (see below), whose sum is σ = 26586546903. Its totient is φ = 23859375552.

The previous prime is 25187911829. The next prime is 25187911883. The reversal of 25187911849 is 94811978152.

The square root of 25187911849 is 158707.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 16619077225 + 8568834624 = 128915^2 + 92568^2 .

It is not a de Polignac number, because 25187911849 - 2⁵ = 25187911817 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 25187911849.

It is not an unprimeable number, because it can be changed into a prime (25187911829) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 3011257 + ... + 3019609.

It is an arithmetic number, because the mean of its divisors is an integer number (2954060767).

Almost surely, 2^25187911849 is an apocalyptic number.

25187911849 is the 158707-th square number.

25187911849 is the 79354-th centered octagonal number.

It is an amenable number.

25187911849 is a deficient number, since it is larger than the sum of its proper divisors (1398635054).

25187911849 is an frugal number, since it uses more digits than its factorization.

25187911849 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16744 (or 8372 counting only the distinct ones).

The product of its digits is 1451520, while the sum is 55.

The spelling of 25187911849 in words is "twenty-five billion, one hundred eighty-seven million, nine hundred eleven thousand, eight hundred forty-nine".