120991243 has 4 divisors (see below), whose sum is σ = 122974768. Its totient is φ = 119007720.

The previous prime is 120991237. The next prime is 120991253. The reversal of 120991243 is 342199021.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 342199021 = 389 ⋅879689.

It is a cyclic number.

It is not a de Polignac number, because 120991243 - 2⁹ = 120990731 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (120991223) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 991671 + ... + 991792.

It is an arithmetic number, because the mean of its divisors is an integer number (30743692).

Almost surely, 2^120991243 is an apocalyptic number.

120991243 is a deficient number, since it is larger than the sum of its proper divisors (1983525).

120991243 is an equidigital number, since it uses as much as digits as its factorization.

120991243 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1983524.

The product of its (nonzero) digits is 3888, while the sum is 31.

The square root of 120991243 is about 10999.6019473434. The cubic root of 120991243 is about 494.5968121120.

The spelling of 120991243 in words is "one hundred twenty million, nine hundred ninety-one thousand, two hundred forty-three".