399246213821 has 16 divisors (see below), whose sum is σ = 491495163264. Its totient is φ = 315813052224.

The previous prime is 399246213787. The next prime is 399246213823. The reversal of 399246213821 is 128312642993.

It is a happy number.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-399246213821 is a prime.

It is a Smith number, since the sum of its digits (50) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a self number, because there is not a number n which added to its sum of digits gives 399246213821.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (399246213823) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 122426 + ... + 901931.

It is an arithmetic number, because the mean of its divisors is an integer number (30718447704).

Almost surely, 2^399246213821 is an apocalyptic number.

It is an amenable number.

399246213821 is a deficient number, since it is larger than the sum of its proper divisors (92248949443).

399246213821 is a wasteful number, since it uses less digits than its factorization.

399246213821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1028660.

The product of its digits is 1119744, while the sum is 50.

The spelling of 399246213821 in words is "three hundred ninety-nine billion, two hundred forty-six million, two hundred thirteen thousand, eight hundred twenty-one".