16840729 has 4 divisors (see below), whose sum is σ = 16989876. Its totient is φ = 16691584.

The previous prime is 16840723. The next prime is 16840739. The reversal of 16840729 is 92704861.

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 1630729 + 15210000 = 1277^2 + 3900^2 .

It is a cyclic number.

It is not a de Polignac number, because 16840729 - 2³ = 16840721 is a prime.

It is a super-2 number, since 2×16840729² = 567220306502882, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (16840721) 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, 74404 + ... + 74629.

It is an arithmetic number, because the mean of its divisors is an integer number (4247469).

Almost surely, 2^16840729 is an apocalyptic number.

It is an amenable number.

16840729 is a deficient number, since it is larger than the sum of its proper divisors (149147).

16840729 is a wasteful number, since it uses less digits than its factorization.

16840729 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 149146.

The product of its (nonzero) digits is 24192, while the sum is 37.

The square root of 16840729 is about 4103.7457279905. The cubic root of 16840729 is about 256.3226370327.

The spelling of 16840729 in words is "sixteen million, eight hundred forty thousand, seven hundred twenty-nine".