21655310122663 has 4 divisors (see below), whose sum is σ = 24748925854480. Its totient is φ = 18561694390848.

The previous prime is 21655310122661. The next prime is 21655310122679. The reversal of 21655310122663 is 36622101355612.

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

It is not a de Polignac number, because 21655310122663 - 2¹ = 21655310122661 is a prime.

It is a super-2 number, since 2×21655310122663² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21655310122661) 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, 1546807865898 + ... + 1546807865911.

It is an arithmetic number, because the mean of its divisors is an integer number (6187231463620).

Almost surely, 2^{21655310122663} is an apocalyptic number.

21655310122663 is a deficient number, since it is larger than the sum of its proper divisors (3093615731817).

21655310122663 is an equidigital number, since it uses as much as digits as its factorization.

21655310122663 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3093615731816.

The product of its (nonzero) digits is 388800, while the sum is 43.

The spelling of 21655310122663 in words is "twenty-one trillion, six hundred fifty-five billion, three hundred ten million, one hundred twenty-two thousand, six hundred sixty-three".