21230213420 has 24 divisors (see below), whose sum is σ = 48012944784. Its totient is φ = 7838847936.

The previous prime is 21230213401. The next prime is 21230213429. The reversal of 21230213420 is 2431203212.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a junction number, because it is equal to n+sod(n) for n = 21230213392 and 21230213401.

It is not an unprimeable number, because it can be changed into a prime (21230213429) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 40827074 + ... + 40827593.

It is an arithmetic number, because the mean of its divisors is an integer number (2000539366).

Almost surely, 2^21230213420 is an apocalyptic number.

21230213420 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21230213420 is an abundant number, since it is smaller than the sum of its proper divisors (26782731364).

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

21230213420 is a wasteful number, since it uses less digits than its factorization.

21230213420 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 81654689 (or 81654687 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 20.

Adding to 21230213420 its reverse (2431203212), we get a palindrome (23661416632).

The spelling of 21230213420 in words is "twenty-one billion, two hundred thirty million, two hundred thirteen thousand, four hundred twenty".