52166721 has 4 divisors (see below), whose sum is σ = 69555632. Its totient is φ = 34777812.

The previous prime is 52166711. The next prime is 52166743. The reversal of 52166721 is 12766125.

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 not a de Polignac number, because 52166721 - 2⁶ = 52166657 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (52166701) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8694451 + ... + 8694456.

It is an arithmetic number, because the mean of its divisors is an integer number (17388908).

Almost surely, 2^52166721 is an apocalyptic number.

It is an amenable number.

52166721 is a deficient number, since it is larger than the sum of its proper divisors (17388911).

52166721 is a wasteful number, since it uses less digits than its factorization.

52166721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17388910.

The product of its digits is 5040, while the sum is 30.

The square root of 52166721 is about 7222.6533213217. The cubic root of 52166721 is about 373.6495926819.

The spelling of 52166721 in words is "fifty-two million, one hundred sixty-six thousand, seven hundred twenty-one".