106321991 has 8 divisors (see below), whose sum is σ = 107627520. Its totient is φ = 105020928.

The previous prime is 106321973. The next prime is 106321997. The reversal of 106321991 is 199123601.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 106321991 - 2²⁶ = 39213127 is a prime.

It is a super-2 number, since 2×106321991² = 22608731540408162, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (106321997) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 82490 + ... + 83768.

It is an arithmetic number, because the mean of its divisors is an integer number (13453440).

Almost surely, 2^106321991 is an apocalyptic number.

106321991 is a deficient number, since it is larger than the sum of its proper divisors (1305529).

106321991 is an equidigital number, since it uses as much as digits as its factorization.

106321991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2233.

The product of its (nonzero) digits is 2916, while the sum is 32.

The square root of 106321991 is about 10311.2555491560. The cubic root of 106321991 is about 473.7410666579.

The spelling of 106321991 in words is "one hundred six million, three hundred twenty-one thousand, nine hundred ninety-one".