21213300042 has 96 divisors (see below), whose sum is σ = 51592282560. Its totient is φ = 6243552000.

The previous prime is 21213300013. The next prime is 21213300079. The reversal of 21213300042 is 24000331212.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a junction number, because it is equal to n+sod(n) for n = 21213299988 and 21213300024.

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, 1853317 + ... + 1864727.

It is an arithmetic number, because the mean of its divisors is an integer number (537419610).

Almost surely, 2^21213300042 is an apocalyptic number.

21213300042 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 21213300042, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25796141280).

21213300042 is an abundant number, since it is smaller than the sum of its proper divisors (30378982518).

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

21213300042 is a wasteful number, since it uses less digits than its factorization.

21213300042 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11700 (or 11697 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 18.

Adding to 21213300042 its reverse (24000331212), we get a palindrome (45213631254).

The spelling of 21213300042 in words is "twenty-one billion, two hundred thirteen million, three hundred thousand, forty-two".