21655416043326 has 16 divisors (see below), whose sum is σ = 46642434555024. Its totient is φ = 6663204936384.

The previous prime is 21655416043321. The next prime is 21655416043423. The reversal of 21655416043326 is 62334061455612.

It is a super-2 number, since 2×21655416043326² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21655416043321) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 138816769431 + ... + 138816769586.

It is an arithmetic number, because the mean of its divisors is an integer number (2915152159689).

Almost surely, 2^{21655416043326} is an apocalyptic number.

21655416043326 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

21655416043326 is an abundant number, since it is smaller than the sum of its proper divisors (24987018511698).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21655416043326 is a wasteful number, since it uses less digits than its factorization.

21655416043326 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 277633539035.

The product of its (nonzero) digits is 3110400, while the sum is 48.

Adding to 21655416043326 its reverse (62334061455612), we get a palindrome (83989477498938).

The spelling of 21655416043326 in words is "twenty-one trillion, six hundred fifty-five billion, four hundred sixteen million, forty-three thousand, three hundred twenty-six".