399805001 has 4 divisors (see below), whose sum is σ = 399953604. Its totient is φ = 399656400.

The previous prime is 399804989. The next prime is 399805019. The reversal of 399805001 is 100508993.

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 88811776 + 310993225 = 9424^2 + 17635^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-399805001 is a prime.

It is a super-2 number, since 2×399805001² = 319688077649220002, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (399805051) 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, 70190 + ... + 75671.

It is an arithmetic number, because the mean of its divisors is an integer number (99988401).

Almost surely, 2^399805001 is an apocalyptic number.

It is an amenable number.

399805001 is a deficient number, since it is larger than the sum of its proper divisors (148603).

399805001 is a wasteful number, since it uses less digits than its factorization.

399805001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 148602.

The product of its (nonzero) digits is 9720, while the sum is 35.

The square root of 399805001 is about 19995.1244307206. The cubic root of 399805001 is about 736.6865498570.

The spelling of 399805001 in words is "three hundred ninety-nine million, eight hundred five thousand, one".