25720165255566 has 16 divisors (see below), whose sum is σ = 51532682996304. Its totient is φ = 8557996337664.

The previous prime is 25720165255517. The next prime is 25720165255607. The reversal of 25720165255566 is 66555256102752.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3848016595 + ... + 3848023278.

It is an arithmetic number, because the mean of its divisors is an integer number (3220792687269).

Almost surely, 2^{25720165255566} is an apocalyptic number.

25720165255566 is an abundant number, since it is smaller than the sum of its proper divisors (25812517740738).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

25720165255566 is a wasteful number, since it uses less digits than its factorization.

25720165255566 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7696040435.

The product of its (nonzero) digits is 37800000, while the sum is 57.

The spelling of 25720165255566 in words is "twenty-five trillion, seven hundred twenty billion, one hundred sixty-five million, two hundred fifty-five thousand, five hundred sixty-six".