1321323021 has 24 divisors (see below), whose sum is σ = 2045397120. Its totient is φ = 819805536.

The previous prime is 1321323001. The next prime is 1321323041. The reversal of 1321323021 is 1203231231.

1321323021 is a `hidden beast` number, since 1 + 321 + 323 + 0 + 21 = 666.

It is an interprime number because it is at equal distance from previous prime (1321323001) and next prime (1321323041).

It is not a de Polignac number, because 1321323021 - 2²² = 1317128717 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1321322985 and 1321323003.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1321323001) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 78601 + ... + 93918.

It is an arithmetic number, because the mean of its divisors is an integer number (85224880).

Almost surely, 2^1321323021 is an apocalyptic number.

It is an amenable number.

1321323021 is a deficient number, since it is larger than the sum of its proper divisors (724074099).

1321323021 is a wasteful number, since it uses less digits than its factorization.

1321323021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 172585 (or 172582 counting only the distinct ones).

The product of its (nonzero) digits is 216, while the sum is 18.

The square root of 1321323021 is about 36350.0071664367. The cubic root of 1321323021 is about 1097.3276787302.

Adding to 1321323021 its reverse (1203231231), we get a palindrome (2524554252).

The spelling of 1321323021 in words is "one billion, three hundred twenty-one million, three hundred twenty-three thousand, twenty-one".