1321011020 has 48 divisors (see below), whose sum is σ = 3173056320. Its totient is φ = 452542464.

The previous prime is 1321011011. The next prime is 1321011023. The reversal of 1321011020 is 201101231.

It is a super-2 number, since 2×1321011020² = 3490140229922880800, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 1321010992 and 1321011010.

It is not an unprimeable number, because it can be changed into a prime (1321011023) 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, 205292 + ... + 211628.

It is an arithmetic number, because the mean of its divisors is an integer number (66105340).

Almost surely, 2^1321011020 is an apocalyptic number.

1321011020 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1321011020 is an abundant number, since it is smaller than the sum of its proper divisors (1852045300).

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

1321011020 is a wasteful number, since it uses less digits than its factorization.

1321011020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7842 (or 7840 counting only the distinct ones).

The product of its (nonzero) digits is 12, while the sum is 11.

The square root of 1321011020 is about 36345.7152908015. The cubic root of 1321011020 is about 1097.2413021015.

Adding to 1321011020 its reverse (201101231), we get a palindrome (1522112251).

The spelling of 1321011020 in words is "one billion, three hundred twenty-one million, eleven thousand, twenty".