2117729 has 2 divisors, whose sum is σ = 2117730. Its totient is φ = 2117728.

The previous prime is 2117723. The next prime is 2117743. The reversal of 2117729 is 9277112.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 2096704 + 21025 = 1448^2 + 145^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2117729 is a prime.

It is a super-2 number, since 2×2117729² = 8969552234882, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (2117723) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1058864 + 1058865.

It is an arithmetic number, because the mean of its divisors is an integer number (1058865).

2^2117729 is an apocalyptic number.

It is an amenable number.

2117729 is a deficient number, since it is larger than the sum of its proper divisors (1).

2117729 is an equidigital number, since it uses as much as digits as its factorization.

2117729 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1764, while the sum is 29.

The square root of 2117729 is about 1455.2419042895. The cubic root of 2117729 is about 128.4172783366.

The spelling of 2117729 in words is "two million, one hundred seventeen thousand, seven hundred twenty-nine".