506221921 has 8 divisors (see below), whose sum is σ = 542920320. Its totient is φ = 470529072.

The previous prime is 506221889. The next prime is 506221949. The reversal of 506221921 is 129122605.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 506221921 - 2⁵ = 506221889 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 506221921.

It is not an unprimeable number, because it can be changed into a prime (506221021) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 250345 + ... + 252358.

It is an arithmetic number, because the mean of its divisors is an integer number (67865040).

Almost surely, 2^506221921 is an apocalyptic number.

It is an amenable number.

506221921 is a deficient number, since it is larger than the sum of its proper divisors (36698399).

506221921 is a wasteful number, since it uses less digits than its factorization.

506221921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 502775.

The product of its (nonzero) digits is 2160, while the sum is 28.

The square root of 506221921 is about 22499.3760135698. The cubic root of 506221921 is about 796.9791916071.

The spelling of 506221921 in words is "five hundred six million, two hundred twenty-one thousand, nine hundred twenty-one".