25767785545 has 4 divisors (see below), whose sum is σ = 30921342660. Its totient is φ = 20614228432.

The previous prime is 25767785531. The next prime is 25767785551. The reversal of 25767785545 is 54558776752.

It is a happy number.

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 11721743289 + 14046042256 = 108267^2 + 118516^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-25767785545 is a prime.

It is a super-2 number, since 2×25767785545² (a number of 22 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2576778550 + ... + 2576778559.

It is an arithmetic number, because the mean of its divisors is an integer number (7730335665).

Almost surely, 2^25767785545 is an apocalyptic number.

It is an amenable number.

25767785545 is a deficient number, since it is larger than the sum of its proper divisors (5153557115).

25767785545 is an equidigital number, since it uses as much as digits as its factorization.

25767785545 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5153557114.

The product of its digits is 82320000, while the sum is 61.

The spelling of 25767785545 in words is "twenty-five billion, seven hundred sixty-seven million, seven hundred eighty-five thousand, five hundred forty-five".