1221021323020 has 48 divisors (see below), whose sum is σ = 2584698076800. Its totient is φ = 484502110976.

The previous prime is 1221021322973. The next prime is 1221021323023. The reversal of 1221021323020 is 203231201221.

It is a super-2 number, since 2×1221021323020² (a number of 25 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (1221021323023) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2038509 + ... + 2568571.

It is an arithmetic number, because the mean of its divisors is an integer number (53847876600).

Almost surely, 2^{1221021323020} is an apocalyptic number.

1221021323020 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1221021323020 is an abundant number, since it is smaller than the sum of its proper divisors (1363676753780).

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

1221021323020 is a wasteful number, since it uses less digits than its factorization.

1221021323020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 530994 (or 530992 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 19.

Adding to 1221021323020 its reverse (203231201221), we get a palindrome (1424252524241).

The spelling of 1221021323020 in words is "one trillion, two hundred twenty-one billion, twenty-one million, three hundred twenty-three thousand, twenty".