634500221 has 4 divisors (see below), whose sum is σ = 637133244. Its totient is φ = 631867200.

The previous prime is 634500199. The next prime is 634500283. The reversal of 634500221 is 122005436.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 362712025 + 271788196 = 19045^2 + 16486^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-634500221 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 (634500121) 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, 1316150 + ... + 1316631.

It is an arithmetic number, because the mean of its divisors is an integer number (159283311).

Almost surely, 2^634500221 is an apocalyptic number.

It is an amenable number.

634500221 is a deficient number, since it is larger than the sum of its proper divisors (2633023).

634500221 is a wasteful number, since it uses less digits than its factorization.

634500221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2633022.

The product of its (nonzero) digits is 1440, while the sum is 23.

The square root of 634500221 is about 25189.2878224058. The cubic root of 634500221 is about 859.2982471635.

Adding to 634500221 its reverse (122005436), we get a palindrome (756505657).

The spelling of 634500221 in words is "six hundred thirty-four million, five hundred thousand, two hundred twenty-one".