1321120020 has 48 divisors (see below), whose sum is σ = 4035423168. Its totient is φ = 320271360.

The previous prime is 1321120013. The next prime is 1321120043. The reversal of 1321120020 is 200211231.

1321120020 is digitally balanced in base 4, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (12).

It is a junction number, because it is equal to n+sod(n) for n = 1321119978 and 1321120005.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1000189 + ... + 1001508.

It is an arithmetic number, because the mean of its divisors is an integer number (84071316).

Almost surely, 2^1321120020 is an apocalyptic number.

1321120020 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1321120020 is an abundant number, since it is smaller than the sum of its proper divisors (2714303148).

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

1321120020 is a wasteful number, since it uses less digits than its factorization.

1321120020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2001720 (or 2001718 counting only the distinct ones).

The product of its (nonzero) digits is 24, while the sum is 12.

The square root of 1321120020 is about 36347.2147488635. The cubic root of 1321120020 is about 1097.2714800008.

Adding to 1321120020 its reverse (200211231), we get a palindrome (1521331251).

The spelling of 1321120020 in words is "one billion, three hundred twenty-one million, one hundred twenty thousand, twenty".