21424804621660 has 96 divisors (see below), whose sum is σ = 51224744051712. Its totient is φ = 7450876139520.

The previous prime is 21424804621607. The next prime is 21424804621667. The reversal of 21424804621660 is 6612640842412.

It is a Harshad number since it is a multiple of its sum of digits (46).

It is a self number, because there is not a number n which added to its sum of digits gives 21424804621660.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21424804621667) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 30585457 + ... + 31278103.

It is an arithmetic number, because the mean of its divisors is an integer number (533591083872).

Almost surely, 2^{21424804621660} is an apocalyptic number.

21424804621660 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21424804621660, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25612372025856).

21424804621660 is an abundant number, since it is smaller than the sum of its proper divisors (29799939430052).

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

21424804621660 is a wasteful number, since it uses less digits than its factorization.

21424804621660 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 698803 (or 698801 counting only the distinct ones).

The product of its (nonzero) digits is 884736, while the sum is 46.

The spelling of 21424804621660 in words is "twenty-one trillion, four hundred twenty-four billion, eight hundred four million, six hundred twenty-one thousand, six hundred sixty".