120665999 has 4 divisors (see below), whose sum is σ = 120689520. Its totient is φ = 120642480.

The previous prime is 120665989. The next prime is 120666019. The reversal of 120665999 is 999566021.

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

It is a cyclic number.

It is not a de Polignac number, because 120665999 - 2¹⁶ = 120600463 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (120665929) 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, 419 + ... + 15540.

It is an arithmetic number, because the mean of its divisors is an integer number (30172380).

Almost surely, 2^120665999 is an apocalyptic number.

120665999 is a deficient number, since it is larger than the sum of its proper divisors (23521).

120665999 is an equidigital number, since it uses as much as digits as its factorization.

120665999 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23520.

The product of its (nonzero) digits is 262440, while the sum is 47.

The square root of 120665999 is about 10984.8076451069. The cubic root of 120665999 is about 494.1532290322.

The spelling of 120665999 in words is "one hundred twenty million, six hundred sixty-five thousand, nine hundred ninety-nine".