2170729 has 4 divisors (see below), whose sum is σ = 2368080. Its totient is φ = 1973380.

The previous prime is 2170723. The next prime is 2170741. The reversal of 2170729 is 9270712.

It is a happy number.

2170729 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, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 2170729 - 2⁵ = 2170697 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 2170697 and 2170706.

It is not an unprimeable number, because it can be changed into a prime (2170723) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 98659 + ... + 98680.

It is an arithmetic number, because the mean of its divisors is an integer number (592020).

2^2170729 is an apocalyptic number.

It is an amenable number.

2170729 is a deficient number, since it is larger than the sum of its proper divisors (197351).

2170729 is a wasteful number, since it uses less digits than its factorization.

2170729 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 197350.

The product of its (nonzero) digits is 1764, while the sum is 28.

The square root of 2170729 is about 1473.3394042107. The cubic root of 2170729 is about 129.4797551374.

It can be divided in two parts, 21707 and 29, that added together give a triangular number (21736 = T₂₀₈).

The spelling of 2170729 in words is "two million, one hundred seventy thousand, seven hundred twenty-nine".