5221216621 has 4 divisors (see below), whose sum is σ = 5233275292. Its totient is φ = 5209157952.

The previous prime is 5221216607. The next prime is 5221216643. The reversal of 5221216621 is 1266121225.

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 1832696100 + 3388520521 = 42810^2 + 58211^2 .

It is a cyclic number.

It is not a de Polignac number, because 5221216621 - 2⁵ = 5221216589 is a prime.

It is a super-2 number, since 2×5221216621² = 54522206006813315282, which contains 22 as substring.

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 5221216621.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (5221216601) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6028686 + ... + 6029551.

It is an arithmetic number, because the mean of its divisors is an integer number (1308318823).

Almost surely, 2^5221216621 is an apocalyptic number.

It is an amenable number.

5221216621 is a deficient number, since it is larger than the sum of its proper divisors (12058671).

5221216621 is a wasteful number, since it uses less digits than its factorization.

5221216621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12058670.

The product of its digits is 2880, while the sum is 28.

The square root of 5221216621 is about 72257.9865551207. The cubic root of 5221216621 is about 1734.8312526792.

Adding to 5221216621 its reverse (1266121225), we get a palindrome (6487337846).

The spelling of 5221216621 in words is "five billion, two hundred twenty-one million, two hundred sixteen thousand, six hundred twenty-one".