8399020391 has 4 divisors (see below), whose sum is σ = 8893080432. Its totient is φ = 7904960352.

The previous prime is 8399020363. The next prime is 8399020453. The reversal of 8399020391 is 1930209938.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1930209938 = 2 ⋅965104969.

It is a cyclic number.

It is not a de Polignac number, because 8399020391 - 2¹⁴ = 8399004007 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 (8399020351) 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, 247029995 + ... + 247030028.

It is an arithmetic number, because the mean of its divisors is an integer number (2223270108).

Almost surely, 2^8399020391 is an apocalyptic number.

8399020391 is a deficient number, since it is larger than the sum of its proper divisors (494060041).

8399020391 is a wasteful number, since it uses less digits than its factorization.

8399020391 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 494060040.

The product of its (nonzero) digits is 104976, while the sum is 44.

The square root of 8399020391 is about 91646.1695380663. The cubic root of 8399020391 is about 2032.7136890483.

The spelling of 8399020391 in words is "eight billion, three hundred ninety-nine million, twenty thousand, three hundred ninety-one".