8120999 has 4 divisors (see below), whose sum is σ = 8548440. Its totient is φ = 7693560.

The previous prime is 8120953. The next prime is 8121011. The reversal of 8120999 is 9990218.

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-8120999 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 (8120599) 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, 213692 + ... + 213729.

It is an arithmetic number, because the mean of its divisors is an integer number (2137110).

Almost surely, 2^8120999 is an apocalyptic number.

8120999 is a deficient number, since it is larger than the sum of its proper divisors (427441).

8120999 is a wasteful number, since it uses less digits than its factorization.

8120999 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 427440.

The product of its (nonzero) digits is 11664, while the sum is 38.

The square root of 8120999 is about 2849.7366544999. The cubic root of 8120999 is about 201.0032836935.

It can be divided in two parts, 8120 and 999, that added together give a palindrome (9119).

The spelling of 8120999 in words is "eight million, one hundred twenty thousand, nine hundred ninety-nine".