121326991 has 4 divisors (see below), whose sum is σ = 121487184. Its totient is φ = 121166800.

The previous prime is 121326983. The next prime is 121327013. The reversal of 121326991 is 199623121.

121326991 is nontrivially palindromic in base 8.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 199623121 = 331 ⋅603091.

It is a cyclic number.

It is not a de Polignac number, because 121326991 - 2³ = 121326983 is a prime.

It is a super-2 number, since 2×121326991² = 29440477490228162, 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 (121326391) 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 3 ways as a sum of consecutive naturals, for example, 78955 + ... + 80476.

It is an arithmetic number, because the mean of its divisors is an integer number (30371796).

Almost surely, 2^121326991 is an apocalyptic number.

121326991 is a deficient number, since it is larger than the sum of its proper divisors (160193).

121326991 is an equidigital number, since it uses as much as digits as its factorization.

121326991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 160192.

The product of its digits is 5832, while the sum is 34.

The square root of 121326991 is about 11014.8531992033. The cubic root of 121326991 is about 495.0538879537.

The spelling of 121326991 in words is "one hundred twenty-one million, three hundred twenty-six thousand, nine hundred ninety-one".