20021221012 has 24 divisors (see below), whose sum is σ = 37865658656. Its totient is φ = 9207904608.

The previous prime is 20021220953. The next prime is 20021221027. The reversal of 20021221012 is 21012212002.

It is a happy number.

It is a super-2 number, since 2×20021221012² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (13).

It is a junction number, because it is equal to n+sod(n) for n = 20021220983 and 20021221001.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 665538 + ... + 694969.

Almost surely, 2^20021221012 is an apocalyptic number.

It is an amenable number.

20021221012 is a deficient number, since it is larger than the sum of its proper divisors (17844437644).

20021221012 is a wasteful number, since it uses less digits than its factorization.

20021221012 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1360807 (or 1360805 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 13.

Adding to 20021221012 its reverse (21012212002), we get a palindrome (41033433014).

The spelling of 20021221012 in words is "twenty billion, twenty-one million, two hundred twenty-one thousand, twelve".