52821661 has 4 divisors (see below), whose sum is σ = 53610112. Its totient is φ = 52033212.

The previous prime is 52821631. The next prime is 52821677. The reversal of 52821661 is 16612825.

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 52821661 - 2⁹ = 52821149 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (52821611) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 394125 + ... + 394258.

It is an arithmetic number, because the mean of its divisors is an integer number (13402528).

Almost surely, 2^52821661 is an apocalyptic number.

It is an amenable number.

52821661 is a deficient number, since it is larger than the sum of its proper divisors (788451).

52821661 is an equidigital number, since it uses as much as digits as its factorization.

52821661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 788450.

The product of its digits is 5760, while the sum is 31.

The square root of 52821661 is about 7267.8511955048. The cubic root of 52821661 is about 375.2067860992.

The spelling of 52821661 in words is "fifty-two million, eight hundred twenty-one thousand, six hundred sixty-one".