399120021001 has 12 divisors (see below), whose sum is σ = 433042521408. Its totient is φ = 367685960304.

The previous prime is 399120020989. The next prime is 399120021061. The reversal of 399120021001 is 100120021993.

It is not a de Polignac number, because 399120021001 - 2⁵ = 399120020969 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (399120021061) 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 11 ways as a sum of consecutive naturals, for example, 2262565 + ... + 2432578.

It is an arithmetic number, because the mean of its divisors is an integer number (36086876784).

Almost surely, 2^399120021001 is an apocalyptic number.

It is an amenable number.

399120021001 is a deficient number, since it is larger than the sum of its proper divisors (33922500407).

399120021001 is a wasteful number, since it uses less digits than its factorization.

399120021001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4695672 (or 4695659 counting only the distinct ones).

The product of its (nonzero) digits is 972, while the sum is 28.

Adding to 399120021001 its reverse (100120021993), we get a palindrome (499240042994).

The spelling of 399120021001 in words is "three hundred ninety-nine billion, one hundred twenty million, twenty-one thousand, one".