399632643 has 16 divisors (see below), whose sum is σ = 623209600. Its totient is φ = 252399240.

The previous prime is 399632641. The next prime is 399632663. The reversal of 399632643 is 346236993.

399632643 is a `hidden beast` number, since 3 + 9 + 9 + 632 + 6 + 4 + 3 = 666.

It is not a de Polignac number, because 399632643 - 2¹ = 399632641 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (399632641) 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, 388993 + ... + 390018.

It is an arithmetic number, because the mean of its divisors is an integer number (38950600).

Almost surely, 2^399632643 is an apocalyptic number.

399632643 is a deficient number, since it is larger than the sum of its proper divisors (223576957).

399632643 is a wasteful number, since it uses less digits than its factorization.

399632643 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 779039 (or 779033 counting only the distinct ones).

The product of its digits is 629856, while the sum is 45.

The square root of 399632643 is about 19990.8139654192. The cubic root of 399632643 is about 736.5806715157.

The spelling of 399632643 in words is "three hundred ninety-nine million, six hundred thirty-two thousand, six hundred forty-three".