8120391 has 16 divisors (see below), whose sum is σ = 11510400. Its totient is φ = 5077728.

The previous prime is 8120383. The next prime is 8120393. The reversal of 8120391 is 1930218.

It is not a de Polignac number, because 8120391 - 2³ = 8120383 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (8120393) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5560 + ... + 6866.

It is an arithmetic number, because the mean of its divisors is an integer number (719400).

Almost surely, 2^8120391 is an apocalyptic number.

8120391 is a deficient number, since it is larger than the sum of its proper divisors (3390009).

8120391 is a wasteful number, since it uses less digits than its factorization.

8120391 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1438.

The product of its (nonzero) digits is 432, while the sum is 24.

The square root of 8120391 is about 2849.6299759793. The cubic root of 8120391 is about 200.9982673547.

The spelling of 8120391 in words is "eight million, one hundred twenty thousand, three hundred ninety-one".