399729073 has 4 divisors (see below), whose sum is σ = 400014180. Its totient is φ = 399443968.

The previous prime is 399729037. The next prime is 399729103. The reversal of 399729073 is 370927993.

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 54066609 + 345662464 = 7353^2 + 18592^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-399729073 is a prime.

It is a Smith number, since the sum of its digits (49) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (399729373) 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, 140440 + ... + 143257.

It is an arithmetic number, because the mean of its divisors is an integer number (100003545).

Almost surely, 2^399729073 is an apocalyptic number.

It is an amenable number.

399729073 is a deficient number, since it is larger than the sum of its proper divisors (285107).

399729073 is a wasteful number, since it uses less digits than its factorization.

399729073 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 285106.

The product of its (nonzero) digits is 642978, while the sum is 49.

The square root of 399729073 is about 19993.2256777139. The cubic root of 399729073 is about 736.6399115562.

The spelling of 399729073 in words is "three hundred ninety-nine million, seven hundred twenty-nine thousand, seventy-three".