25561898 has 4 divisors (see below), whose sum is σ = 38342850. Its totient is φ = 12780948.

The previous prime is 25561891. The next prime is 25561969. The reversal of 25561898 is 89816552.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 12909649 + 12652249 = 3593^2 + 3557^2 .

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (25561891) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6390473 + ... + 6390476.

Almost surely, 2^25561898 is an apocalyptic number.

25561898 is a deficient number, since it is larger than the sum of its proper divisors (12780952).

25561898 is a wasteful number, since it uses less digits than its factorization.

25561898 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12780951.

The product of its digits is 172800, while the sum is 44.

The square root of 25561898 is about 5055.8775697202. The cubic root of 25561898 is about 294.5762296145.

The spelling of 25561898 in words is "twenty-five million, five hundred sixty-one thousand, eight hundred ninety-eight".