39940729 has 4 divisors (see below), whose sum is σ = 39973284. Its totient is φ = 39908176.

The previous prime is 39940711. The next prime is 39940751. The reversal of 39940729 is 92704993.

39940729 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 24730729 + 15210000 = 4973^2 + 3900^2 .

It is a cyclic number.

It is not a de Polignac number, because 39940729 - 2⁵ = 39940697 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (39940129) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 14362 + ... + 16915.

It is an arithmetic number, because the mean of its divisors is an integer number (9993321).

Almost surely, 2^39940729 is an apocalyptic number.

It is an amenable number.

39940729 is a deficient number, since it is larger than the sum of its proper divisors (32555).

39940729 is a wasteful number, since it uses less digits than its factorization.

39940729 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32554.

The product of its (nonzero) digits is 122472, while the sum is 43.

The square root of 39940729 is about 6319.8677992502. The cubic root of 39940729 is about 341.8261858589.

The spelling of 39940729 in words is "thirty-nine million, nine hundred forty thousand, seven hundred twenty-nine".