2172566634655 has 4 divisors (see below), whose sum is σ = 2607079961592. Its totient is φ = 1738053307720.

The previous prime is 2172566634647. The next prime is 2172566634673. The reversal of 2172566634655 is 5564366652712.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 2172566634655 - 2³ = 2172566634647 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 2172566634655.

It is a congruent number.

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, 217256663461 + ... + 217256663470.

It is an arithmetic number, because the mean of its divisors is an integer number (651769990398).

Almost surely, 2^{2172566634655} is an apocalyptic number.

2172566634655 is a deficient number, since it is larger than the sum of its proper divisors (434513326937).

2172566634655 is an equidigital number, since it uses as much as digits as its factorization.

2172566634655 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 434513326936.

The product of its digits is 54432000, while the sum is 58.

The spelling of 2172566634655 in words is "two trillion, one hundred seventy-two billion, five hundred sixty-six million, six hundred thirty-four thousand, six hundred fifty-five".