25515549989 has 4 divisors (see below), whose sum is σ = 25606352940. Its totient is φ = 25424747040.

The previous prime is 25515549919. The next prime is 25515550007. The reversal of 25515549989 is 98994551552.

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 14706412900 + 10809137089 = 121270^2 + 103967^2 .

It is a cyclic number.

It is not a de Polignac number, because 25515549989 - 2¹⁶ = 25515484453 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (25515549919) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 45401054 + ... + 45401615.

It is an arithmetic number, because the mean of its divisors is an integer number (6401588235).

Almost surely, 2^25515549989 is an apocalyptic number.

It is an amenable number.

25515549989 is a deficient number, since it is larger than the sum of its proper divisors (90802951).

25515549989 is an equidigital number, since it uses as much as digits as its factorization.

25515549989 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 90802950.

The product of its digits is 29160000, while the sum is 62.

The spelling of 25515549989 in words is "twenty-five billion, five hundred fifteen million, five hundred forty-nine thousand, nine hundred eighty-nine".