120999999 has 32 divisors (see below), whose sum is σ = 181025280. Its totient is φ = 71442432.

The previous prime is 120999997. The next prime is 121000003. The reversal of 120999999 is 999999021.

It is a Cunningham number, because it is equal to 11000²-1.

It is not a de Polignac number, because 120999999 - 2¹ = 120999997 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (57).

120999999 is a modest number, since divided by 99999 gives 1209 as remainder.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (120999997) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 186694 + ... + 187340.

It is an arithmetic number, because the mean of its divisors is an integer number (5657040).

Almost surely, 2^120999999 is an apocalyptic number.

120999999 is a gapful number since it is divisible by the number (19) formed by its first and last digit.

120999999 is a deficient number, since it is larger than the sum of its proper divisors (60025281).

120999999 is a wasteful number, since it uses less digits than its factorization.

120999999 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 879.

The product of its (nonzero) digits is 1062882, while the sum is 57.

The square root of 120999999 is about 10999.9999545455. Note that the first 4 decimals coincide. The cubic root of 120999999 is about 494.6087429623.

The spelling of 120999999 in words is "one hundred twenty million, nine hundred ninety-nine thousand, nine hundred ninety-nine".