21442021215420 has 144 divisors (see below), whose sum is σ = 65017592220672. Its totient is φ = 5277516491520.

The previous prime is 21442021215409. The next prime is 21442021215449. The reversal of 21442021215420 is 2451212024412.

21442021215420 is digitally balanced in base 5 and base 6, because in such bases it contains all the possibile digits an equal number of times.

It is a super-3 number, since 3×21442021215420³ (a number of 41 digits) contains 333 as substring.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 108510829 + ... + 108708251.

It is an arithmetic number, because the mean of its divisors is an integer number (451511057088).

Almost surely, 2^{21442021215420} is an apocalyptic number.

21442021215420 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 21442021215420, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32508796110336).

21442021215420 is an abundant number, since it is smaller than the sum of its proper divisors (43575571005252).

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

21442021215420 is a wasteful number, since it uses less digits than its factorization.

21442021215420 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 208172 (or 208157 counting only the distinct ones).

The product of its (nonzero) digits is 10240, while the sum is 30.

Adding to 21442021215420 its reverse (2451212024412), we get a palindrome (23893233239832).

The spelling of 21442021215420 in words is "twenty-one trillion, four hundred forty-two billion, twenty-one million, two hundred fifteen thousand, four hundred twenty".