21655234666626 has 128 divisors (see below), whose sum is σ = 48910820032512. Its totient is φ = 6335491680000.

The previous prime is 21655234666619. The next prime is 21655234666697. The reversal of 21655234666626 is 62666643255612.

It is a self number, because there is not a number n which added to its sum of digits gives 21655234666626.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 84777316 + ... + 85032368.

It is an arithmetic number, because the mean of its divisors is an integer number (382115781504).

Almost surely, 2^{21655234666626} is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21655234666626, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24455410016256).

21655234666626 is an abundant number, since it is smaller than the sum of its proper divisors (27255585365886).

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

21655234666626 is a wasteful number, since it uses less digits than its factorization.

21655234666626 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 255488.

The product of its digits is 111974400, while the sum is 60.

The spelling of 21655234666626 in words is "twenty-one trillion, six hundred fifty-five billion, two hundred thirty-four million, six hundred sixty-six thousand, six hundred twenty-six".