25021861489 has 9 divisors (see below), whose sum is σ = 25151447307. Its totient is φ = 24892942344.

The previous prime is 25021861471. The next prime is 25021861493. The reversal of 25021861489 is 98416812052.

The square root of 25021861489 is 158183.

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., 1400630625 + 23621230864 = 37425^2 + 153692^2 .

It is a de Polignac number, because none of the positive numbers 2^k-25021861489 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (25021861589) 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, 50143762 + ... + 50144260.

Almost surely, 2^25021861489 is an apocalyptic number.

25021861489 is the 158183-rd square number.

25021861489 is the 79092-nd centered octagonal number.

It is an amenable number.

25021861489 is a deficient number, since it is larger than the sum of its proper divisors (129585818).

25021861489 is an frugal number, since it uses more digits than its factorization.

25021861489 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1632 (or 816 counting only the distinct ones).

The product of its (nonzero) digits is 276480, while the sum is 46.

The spelling of 25021861489 in words is "twenty-five billion, twenty-one million, eight hundred sixty-one thousand, four hundred eighty-nine".