25434521787 has 6 divisors (see below), whose sum is σ = 33913064028. Its totient is φ = 16956163704.

The previous prime is 25434521773. The next prime is 25434521803. The reversal of 25434521787 is 78712543452.

It is a happy number.

It is not a de Polignac number, because 25434521787 - 2⁸ = 25434521531 is a prime.

It is not an unprimeable number, because it can be changed into a prime (25434521767) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 230193 + ... + 322269.

It is an arithmetic number, because the mean of its divisors is an integer number (5652177338).

Almost surely, 2^25434521787 is an apocalyptic number.

25434521787 is a deficient number, since it is larger than the sum of its proper divisors (8478542241).

25434521787 is an frugal number, since it uses more digits than its factorization.

25434521787 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 184157 (or 92080 counting only the distinct ones).

The product of its digits is 1881600, while the sum is 48.

Multiplying 25434521787 by its sum of digits (48), we get a square (1220857045776 = 1104924²).

The spelling of 25434521787 in words is "twenty-five billion, four hundred thirty-four million, five hundred twenty-one thousand, seven hundred eighty-seven".