2561666455 has 8 divisors (see below), whose sum is σ = 3074524704. Its totient is φ = 2048983200.

The previous prime is 2561666417. The next prime is 2561666461. The reversal of 2561666455 is 5546661652.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 2561666455 - 2¹¹ = 2561664407 is a prime.

It is a Duffinian number.

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, 9036 + ... + 72145.

It is an arithmetic number, because the mean of its divisors is an integer number (384315588).

Almost surely, 2^2561666455 is an apocalyptic number.

2561666455 is a deficient number, since it is larger than the sum of its proper divisors (512858249).

2561666455 is an equidigital number, since it uses as much as digits as its factorization.

2561666455 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 87497.

The product of its digits is 1296000, while the sum is 46.

The square root of 2561666455 is about 50612.9079879827. The cubic root of 2561666455 is about 1368.2775260774.

The spelling of 2561666455 in words is "two billion, five hundred sixty-one million, six hundred sixty-six thousand, four hundred fifty-five".