1320431021 has 16 divisors (see below), whose sum is σ = 1720744704. Its totient is φ = 983280384.

The previous prime is 1320431017. The next prime is 1320431053. The reversal of 1320431021 is 1201340231.

It is a cyclic number.

It is not a de Polignac number, because 1320431021 - 2² = 1320431017 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (17).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1320430021) 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 15 ways as a sum of consecutive naturals, for example, 425225 + ... + 428318.

It is an arithmetic number, because the mean of its divisors is an integer number (107546544).

Almost surely, 2^1320431021 is an apocalyptic number.

It is an amenable number.

1320431021 is a deficient number, since it is larger than the sum of its proper divisors (400313683).

1320431021 is a wasteful number, since it uses less digits than its factorization.

1320431021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 853580.

The product of its (nonzero) digits is 144, while the sum is 17.

The square root of 1320431021 is about 36337.7354963129. The cubic root of 1320431021 is about 1097.0806948066.

Adding to 1320431021 its reverse (1201340231), we get a palindrome (2521771252).

The spelling of 1320431021 in words is "one billion, three hundred twenty million, four hundred thirty-one thousand, twenty-one".