21224140042420 has 48 divisors (see below), whose sum is σ = 51442272137088. Its totient is φ = 7204800009600.

The previous prime is 21224140042349. The next prime is 21224140042421. The reversal of 21224140042420 is 2424004142212.

It is a happy number.

It is a Smith number, since the sum of its digits (28) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (28).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21224140042421) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 750485862 + ... + 750514141.

It is an arithmetic number, because the mean of its divisors is an integer number (1071714002856).

Almost surely, 2^{21224140042420} is an apocalyptic number.

21224140042420 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21224140042420 is an abundant number, since it is smaller than the sum of its proper divisors (30218132094668).

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

21224140042420 is a wasteful number, since it uses less digits than its factorization.

21224140042420 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1501000120 (or 1501000118 counting only the distinct ones).

The product of its (nonzero) digits is 8192, while the sum is 28.

Adding to 21224140042420 its reverse (2424004142212), we get a palindrome (23648144184632).

The spelling of 21224140042420 in words is "twenty-one trillion, two hundred twenty-four billion, one hundred forty million, forty-two thousand, four hundred twenty".