21655224342511 has 4 divisors (see below), whose sum is σ = 21662057802400. Its totient is φ = 21648390882624.

The previous prime is 21655224342431. The next prime is 21655224342547. The reversal of 21655224342511 is 11524342255612.

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 21655224342511 - 2²¹ = 21655222245359 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21655224342551) 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, 3416725191 + ... + 3416731528.

It is an arithmetic number, because the mean of its divisors is an integer number (5415514450600).

Almost surely, 2^{21655224342511} is an apocalyptic number.

21655224342511 is a deficient number, since it is larger than the sum of its proper divisors (6833459889).

21655224342511 is an equidigital number, since it uses as much as digits as its factorization.

21655224342511 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6833459888.

The product of its digits is 576000, while the sum is 43.

The spelling of 21655224342511 in words is "twenty-one trillion, six hundred fifty-five billion, two hundred twenty-four million, three hundred forty-two thousand, five hundred eleven".