399830869 has 4 divisors (see below), whose sum is σ = 399873420. Its totient is φ = 399788320.

The previous prime is 399830807. The next prime is 399830897. The reversal of 399830869 is 968038993.

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, and also an emirpimes, since its reverse is a distinct semiprime: 968038993 = 2371 ⋅408283.

It can be written as a sum of positive squares in 2 ways, for example, as 207648100 + 192182769 = 14410^2 + 13863^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-399830869 is a prime.

It is a super-2 number, since 2×399830869² = 319729447610590322, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (399830069) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 262 + ... + 28279.

It is an arithmetic number, because the mean of its divisors is an integer number (99968355).

Almost surely, 2^399830869 is an apocalyptic number.

It is an amenable number.

399830869 is a deficient number, since it is larger than the sum of its proper divisors (42551).

399830869 is a wasteful number, since it uses less digits than its factorization.

399830869 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 42550.

The product of its (nonzero) digits is 2519424, while the sum is 55.

The square root of 399830869 is about 19995.7712779477. The cubic root of 399830869 is about 736.7024377662.

The spelling of 399830869 in words is "three hundred ninety-nine million, eight hundred thirty thousand, eight hundred sixty-nine".