321072109 has 2 divisors, whose sum is σ = 321072110. Its totient is φ = 321072108.

The previous prime is 321072091. The next prime is 321072113. The reversal of 321072109 is 901270123.

Together with previous prime (321072091) it forms an Ormiston pair, because they use the same digits, order apart.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 201782025 + 119290084 = 14205^2 + 10922^2 .

It is a cyclic number.

It is not a de Polignac number, because 321072109 - 2¹⁷ = 320941037 is a prime.

It is an alternating number because its digits alternate between odd and even.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (321072119) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 160536054 + 160536055.

It is an arithmetic number, because the mean of its divisors is an integer number (160536055).

Almost surely, 2^321072109 is an apocalyptic number.

It is an amenable number.

321072109 is a deficient number, since it is larger than the sum of its proper divisors (1).

321072109 is an equidigital number, since it uses as much as digits as its factorization.

321072109 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 756, while the sum is 25.

The square root of 321072109 is about 17918.4851201211. The cubic root of 321072109 is about 684.7533941011.

The spelling of 321072109 in words is "three hundred twenty-one million, seventy-two thousand, one hundred nine".