21020221212 has 48 divisors (see below), whose sum is σ = 50663424000. Its totient is φ = 6776153280.

The previous prime is 21020221153. The next prime is 21020221259. The reversal of 21020221212 is 21212202012.

It is a super-3 number, since 3×21020221212³ (a number of 32 digits) contains 333 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21020221191 and 21020221200.

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 15 ways as a sum of consecutive naturals, for example, 557989 + ... + 594467.

It is an arithmetic number, because the mean of its divisors is an integer number (1055488000).

Almost surely, 2^21020221212 is an apocalyptic number.

It is an amenable number.

21020221212 is an abundant number, since it is smaller than the sum of its proper divisors (29643202788).

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

21020221212 is a wasteful number, since it uses less digits than its factorization.

21020221212 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 38066 (or 38064 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 15.

Adding to 21020221212 its reverse (21212202012), we get a palindrome (42232423224).

The spelling of 21020221212 in words is "twenty-one billion, twenty million, two hundred twenty-one thousand, two hundred twelve".