1321012021 has 32 divisors (see below), whose sum is σ = 1599488000. Its totient is φ = 1089411120.

The previous prime is 1321012019. The next prime is 1321012037. The reversal of 1321012021 is 1202101231.

It is not a de Polignac number, because 1321012021 - 2¹ = 1321012019 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1321011992 and 1321012010.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1321012051) by changing a digit.

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 31 ways as a sum of consecutive naturals, for example, 3008920 + ... + 3009358.

It is an arithmetic number, because the mean of its divisors is an integer number (49984000).

Almost surely, 2^1321012021 is an apocalyptic number.

It is an amenable number.

1321012021 is a deficient number, since it is larger than the sum of its proper divisors (278475979).

1321012021 is an equidigital number, since it uses as much as digits as its factorization.

1321012021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 774 (or 760 counting only the distinct ones).

The product of its (nonzero) digits is 24, while the sum is 13.

The square root of 1321012021 is about 36345.7290613354. The cubic root of 1321012021 is about 1097.2415792473.

Adding to 1321012021 its reverse (1202101231), we get a palindrome (2523113252).

The spelling of 1321012021 in words is "one billion, three hundred twenty-one million, twelve thousand, twenty-one".