21202412220 has 72 divisors (see below), whose sum is σ = 70160716080. Its totient is φ = 5139978240.

The previous prime is 21202412201. The next prime is 21202412233. The reversal of 21202412220 is 2221420212.

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 = 21202412193 and 21202412202.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 5352165 + ... + 5356124.

It is an arithmetic number, because the mean of its divisors is an integer number (974454390).

Almost surely, 2^21202412220 is an apocalyptic number.

21202412220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21202412220 is an abundant number, since it is smaller than the sum of its proper divisors (48958303860).

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

21202412220 is a wasteful number, since it uses less digits than its factorization.

21202412220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10708315 (or 10708310 counting only the distinct ones).

The product of its (nonzero) digits is 256, while the sum is 18.

Adding to 21202412220 its reverse (2221420212), we get a palindrome (23423832432).

The spelling of 21202412220 in words is "twenty-one billion, two hundred two million, four hundred twelve thousand, two hundred twenty".