120721999 has 4 divisors (see below), whose sum is σ = 123666480. Its totient is φ = 117777520.

The previous prime is 120721973. The next prime is 120722011. The reversal of 120721999 is 999127021.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-120721999 is a prime.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (120721919) 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, 1472179 + ... + 1472260.

It is an arithmetic number, because the mean of its divisors is an integer number (30916620).

Almost surely, 2^120721999 is an apocalyptic number.

120721999 is a deficient number, since it is larger than the sum of its proper divisors (2944481).

120721999 is an equidigital number, since it uses as much as digits as its factorization.

120721999 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2944480.

The product of its (nonzero) digits is 20412, while the sum is 40.

The square root of 120721999 is about 10987.3563244304. The cubic root of 120721999 is about 494.2296612260.

The spelling of 120721999 in words is "one hundred twenty million, seven hundred twenty-one thousand, nine hundred ninety-nine".