1012321021 has 4 divisors (see below), whose sum is σ = 1012386492. Its totient is φ = 1012255552.

The previous prime is 1012321001. The next prime is 1012321031. The reversal of 1012321021 is 1201232101.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 1201232101 = 1889 ⋅635909.

It can be written as a sum of positive squares in 2 ways, for example, as 308002500 + 704318521 = 17550^2 + 26539^2 .

It is a cyclic number.

It is not a de Polignac number, because 1012321021 - 2⁵ = 1012320989 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1012320992 and 1012321010.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1012321001) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4821 + ... + 45253.

It is an arithmetic number, because the mean of its divisors is an integer number (253096623).

Almost surely, 2^1012321021 is an apocalyptic number.

It is an amenable number.

1012321021 is a deficient number, since it is larger than the sum of its proper divisors (65471).

1012321021 is an equidigital number, since it uses as much as digits as its factorization.

1012321021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 65470.

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

The square root of 1012321021 is about 31816.9926454403. The cubic root of 1012321021 is about 1004.0902540119.

Adding to 1012321021 its reverse (1201232101), we get a palindrome (2213553122).

The spelling of 1012321021 in words is "one billion, twelve million, three hundred twenty-one thousand, twenty-one".