1221322020 has 48 divisors (see below), whose sum is σ = 3429615168. Its totient is φ = 324741760.

The previous prime is 1221322013. The next prime is 1221322021. The reversal of 1221322020 is 202231221.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is not an unprimeable number, because it can be changed into a prime (1221322021) 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, 8511 + ... + 50150.

It is an arithmetic number, because the mean of its divisors is an integer number (71450316).

Almost surely, 2^1221322020 is an apocalyptic number.

1221322020 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1221322020 is an abundant number, since it is smaller than the sum of its proper divisors (2208293148).

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

1221322020 is a wasteful number, since it uses less digits than its factorization.

1221322020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 59020 (or 59018 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 15.

The square root of 1221322020 is about 34947.4179303708. The cubic root of 1221322020 is about 1068.9155519337.

Adding to 1221322020 its reverse (202231221), we get a palindrome (1423553241).

The spelling of 1221322020 in words is "one billion, two hundred twenty-one million, three hundred twenty-two thousand, twenty".