321120991 has 2 divisors, whose sum is σ = 321120992. Its totient is φ = 321120990.

The previous prime is 321120983. The next prime is 321121067. The reversal of 321120991 is 199021123.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 321120991 - 2³ = 321120983 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (321120901) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 160560495 + 160560496.

It is an arithmetic number, because the mean of its divisors is an integer number (160560496).

Almost surely, 2^321120991 is an apocalyptic number.

321120991 is a deficient number, since it is larger than the sum of its proper divisors (1).

321120991 is an equidigital number, since it uses as much as digits as its factorization.

321120991 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 972, while the sum is 28.

The square root of 321120991 is about 17919.8490786055. The cubic root of 321120991 is about 684.7881426990.

The spelling of 321120991 in words is "three hundred twenty-one million, one hundred twenty thousand, nine hundred ninety-one".