399011201021 has 4 divisors (see below), whose sum is σ = 399022315452. Its totient is φ = 399000086592.

The previous prime is 399011201011. The next prime is 399011201107. The reversal of 399011201021 is 120102110993.

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 191677596100 + 207333604921 = 437810^2 + 455339^2 .

It is a cyclic number.

It is not a de Polignac number, because 399011201021 - 2¹⁰ = 399011199997 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (399011201011) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5503190 + ... + 5575223.

It is an arithmetic number, because the mean of its divisors is an integer number (99755578863).

Almost surely, 2^399011201021 is an apocalyptic number.

It is an amenable number.

399011201021 is a deficient number, since it is larger than the sum of its proper divisors (11114431).

399011201021 is a wasteful number, since it uses less digits than its factorization.

399011201021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11114430.

The product of its (nonzero) digits is 972, while the sum is 29.

The spelling of 399011201021 in words is "three hundred ninety-nine billion, eleven million, two hundred one thousand, twenty-one".