1320221091 has 32 divisors (see below), whose sum is σ = 2103349248. Its totient is φ = 720197280.

The previous prime is 1320221083. The next prime is 1320221129. The reversal of 1320221091 is 1901220231.

It is not a de Polignac number, because 1320221091 - 2³ = 1320221083 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is not an unprimeable number, because it can be changed into a prime (1320221011) 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, 273400 + ... + 278186.

It is an arithmetic number, because the mean of its divisors is an integer number (65729664).

Almost surely, 2^1320221091 is an apocalyptic number.

1320221091 is a deficient number, since it is larger than the sum of its proper divisors (783128157).

1320221091 is a wasteful number, since it uses less digits than its factorization.

1320221091 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5391.

The product of its (nonzero) digits is 216, while the sum is 21.

The square root of 1320221091 is about 36334.8467865216. The cubic root of 1320221091 is about 1097.0225515809.

The spelling of 1320221091 in words is "one billion, three hundred twenty million, two hundred twenty-one thousand, ninety-one".