399861829 has 4 divisors (see below), whose sum is σ = 405829984. Its totient is φ = 393893676.

The previous prime is 399861827. The next prime is 399861841. The reversal of 399861829 is 928168993.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 399861829 - 2¹ = 399861827 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 399861829.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (399861827) 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, 2983977 + ... + 2984110.

It is an arithmetic number, because the mean of its divisors is an integer number (101457496).

Almost surely, 2^399861829 is an apocalyptic number.

It is an amenable number.

399861829 is a deficient number, since it is larger than the sum of its proper divisors (5968155).

399861829 is an equidigital number, since it uses as much as digits as its factorization.

399861829 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5968154.

The product of its digits is 1679616, while the sum is 55.

The square root of 399861829 is about 19996.5454266481. The cubic root of 399861829 is about 736.7214522384.

The spelling of 399861829 in words is "three hundred ninety-nine million, eight hundred sixty-one thousand, eight hundred twenty-nine".