399809164049 has 4 divisors (see below), whose sum is σ = 407352733236. Its totient is φ = 392265594864.

The previous prime is 399809164037. The next prime is 399809164087. The reversal of 399809164049 is 940461908993.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 196277353024 + 203531811025 = 443032^2 + 451145^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-399809164049 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 399809163982 and 399809164000.

It is not an unprimeable number, because it can be changed into a prime (399809164009) 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, 3771784514 + ... + 3771784619.

It is an arithmetic number, because the mean of its divisors is an integer number (101838183309).

Almost surely, 2^399809164049 is an apocalyptic number.

It is an amenable number.

399809164049 is a deficient number, since it is larger than the sum of its proper divisors (7543569187).

399809164049 is an equidigital number, since it uses as much as digits as its factorization.

399809164049 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7543569186.

The product of its (nonzero) digits is 15116544, while the sum is 62.

It can be divided in two parts, 39980 and 9164049, that added together give a palindrome (9204029).

The spelling of 399809164049 in words is "three hundred ninety-nine billion, eight hundred nine million, one hundred sixty-four thousand, forty-nine".