21366431220630 has 128 divisors (see below), whose sum is σ = 52874563622400. Its totient is φ = 5523337257984.

The previous prime is 21366431220623. The next prime is 21366431220689. The reversal of 21366431220630 is 3602213466312.

It is a congruent number.

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, 64313586 + ... + 64644954.

It is an arithmetic number, because the mean of its divisors is an integer number (413082528300).

Almost surely, 2^{21366431220630} is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21366431220630, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26437281811200).

21366431220630 is an abundant number, since it is smaller than the sum of its proper divisors (31508132401770).

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

21366431220630 is a wasteful number, since it uses less digits than its factorization.

21366431220630 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 331918.

The product of its (nonzero) digits is 186624, while the sum is 39.

Adding to 21366431220630 its reverse (3602213466312), we get a palindrome (24968644686942).

The spelling of 21366431220630 in words is "twenty-one trillion, three hundred sixty-six billion, four hundred thirty-one million, two hundred twenty thousand, six hundred thirty".