120391989 has 4 divisors (see below), whose sum is σ = 160522656. Its totient is φ = 80261324.

The previous prime is 120391987. The next prime is 120391993. The reversal of 120391989 is 989193021.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 989193021 = 3 ⋅329731007.

It is a cyclic number.

It is not a de Polignac number, because 120391989 - 2¹ = 120391987 is a prime.

It is a super-2 number, since 2×120391989² = 28988462030752242, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 120391989.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (120391987) 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 3 ways as a sum of consecutive naturals, for example, 20065329 + ... + 20065334.

It is an arithmetic number, because the mean of its divisors is an integer number (40130664).

Almost surely, 2^120391989 is an apocalyptic number.

It is an amenable number.

120391989 is a deficient number, since it is larger than the sum of its proper divisors (40130667).

120391989 is an equidigital number, since it uses as much as digits as its factorization.

120391989 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40130666.

The product of its (nonzero) digits is 34992, while the sum is 42.

The square root of 120391989 is about 10972.3283308512. The cubic root of 120391989 is about 493.7789022445.

It can be divided in two parts, 12039 and 1989, that added together give a triangular number (14028 = T₁₆₇).

The spelling of 120391989 in words is "one hundred twenty million, three hundred ninety-one thousand, nine hundred eighty-nine".