2155631643663 has 4 divisors (see below), whose sum is σ = 2874175524888. Its totient is φ = 1437087762440.

The previous prime is 2155631643653. The next prime is 2155631643677. The reversal of 2155631643663 is 3663461365512.

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

It is a cyclic number.

It is not a de Polignac number, because 2155631643663 - 2⁵ = 2155631643631 is a prime.

It is a super-2 number, since 2×2155631643663² (a number of 25 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2155631643653) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 359271940608 + ... + 359271940613.

It is an arithmetic number, because the mean of its divisors is an integer number (718543881222).

Almost surely, 2^{2155631643663} is an apocalyptic number.

2155631643663 is a deficient number, since it is larger than the sum of its proper divisors (718543881225).

2155631643663 is an equidigital number, since it uses as much as digits as its factorization.

2155631643663 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 718543881224.

The product of its digits is 6998400, while the sum is 51.

The spelling of 2155631643663 in words is "two trillion, one hundred fifty-five billion, six hundred thirty-one million, six hundred forty-three thousand, six hundred sixty-three".