1320021243 has 6 divisors (see below), whose sum is σ = 1906697364. Its totient is φ = 880014156.

The previous prime is 1320021169. The next prime is 1320021289. The reversal of 1320021243 is 3421200231.

It is not a de Polignac number, because 1320021243 - 2⁸ = 1320020987 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1320021343) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 73334505 + ... + 73334522.

It is an arithmetic number, because the mean of its divisors is an integer number (317782894).

Almost surely, 2^1320021243 is an apocalyptic number.

1320021243 is a deficient number, since it is larger than the sum of its proper divisors (586676121).

1320021243 is a wasteful number, since it uses less digits than its factorization.

1320021243 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 146669033 (or 146669030 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 18.

The square root of 1320021243 is about 36332.0965951595. The cubic root of 1320021243 is about 1096.9671949876.

Adding to 1320021243 its reverse (3421200231), we get a palindrome (4741221474).

It can be divided in two parts, 13200 and 21243, that added together give a palindrome (34443).

The spelling of 1320021243 in words is "one billion, three hundred twenty million, twenty-one thousand, two hundred forty-three".