869720399 has 4 divisors (see below), whose sum is σ = 869802264. Its totient is φ = 869638536.

The previous prime is 869720389. The next prime is 869720417. The reversal of 869720399 is 993027968.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 869720399 - 2²⁰ = 868671823 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 869720399.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (869720329) 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, 22112 + ... + 47205.

It is an arithmetic number, because the mean of its divisors is an integer number (217450566).

Almost surely, 2^869720399 is an apocalyptic number.

869720399 is a deficient number, since it is larger than the sum of its proper divisors (81865).

869720399 is a wasteful number, since it uses less digits than its factorization.

869720399 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 81864.

The product of its (nonzero) digits is 1469664, while the sum is 53.

The square root of 869720399 is about 29491.0223457919. The cubic root of 869720399 is about 954.5379924021.

The spelling of 869720399 in words is "eight hundred sixty-nine million, seven hundred twenty thousand, three hundred ninety-nine".