2166836521 has 4 divisors (see below), whose sum is σ = 2217228112. Its totient is φ = 2116444932.

The previous prime is 2166836489. The next prime is 2166836531. The reversal of 2166836521 is 1256386612.

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 2166836521 - 2⁵ = 2166836489 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2166836531) 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, 25195731 + ... + 25195816.

It is an arithmetic number, because the mean of its divisors is an integer number (554307028).

Almost surely, 2^2166836521 is an apocalyptic number.

It is an amenable number.

2166836521 is a deficient number, since it is larger than the sum of its proper divisors (50391591).

2166836521 is an equidigital number, since it uses as much as digits as its factorization.

2166836521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 50391590.

The product of its digits is 103680, while the sum is 40.

The square root of 2166836521 is about 46549.2913050242. The cubic root of 2166836521 is about 1294.0231590255.

The spelling of 2166836521 in words is "two billion, one hundred sixty-six million, eight hundred thirty-six thousand, five hundred twenty-one".