25666720539 has 16 divisors (see below), whose sum is σ = 34956168192. Its totient is φ = 16744329728.

The previous prime is 25666720507. The next prime is 25666720543. The reversal of 25666720539 is 93502766652.

It is a cyclic number.

It is not a de Polignac number, because 25666720539 - 2⁵ = 25666720507 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 25666720491 and 25666720500.

It is not an unprimeable number, because it can be changed into a prime (25666720549) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1189642 + ... + 1211024.

It is an arithmetic number, because the mean of its divisors is an integer number (2184760512).

Almost surely, 2^25666720539 is an apocalyptic number.

25666720539 is a deficient number, since it is larger than the sum of its proper divisors (9289447653).

25666720539 is a wasteful number, since it uses less digits than its factorization.

25666720539 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29946.

The product of its (nonzero) digits is 4082400, while the sum is 51.

The spelling of 25666720539 in words is "twenty-five billion, six hundred sixty-six million, seven hundred twenty thousand, five hundred thirty-nine".