5206721221 has 16 divisors (see below), whose sum is σ = 5906658240. Its totient is φ = 4549927680.

The previous prime is 5206721213. The next prime is 5206721231. The reversal of 5206721221 is 1221276025.

It is a cyclic number.

It is not a de Polignac number, because 5206721221 - 2³ = 5206721213 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 5206721221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (5206721231) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 369261 + ... + 383101.

It is an arithmetic number, because the mean of its divisors is an integer number (369166140).

Almost surely, 2^5206721221 is an apocalyptic number.

It is an amenable number.

5206721221 is a deficient number, since it is larger than the sum of its proper divisors (699937019).

5206721221 is a wasteful number, since it uses less digits than its factorization.

5206721221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15396.

The product of its (nonzero) digits is 3360, while the sum is 28.

The square root of 5206721221 is about 72157.6137424181. The cubic root of 5206721221 is about 1733.2243232192.

Adding to 5206721221 its reverse (1221276025), we get a palindrome (6427997246).

The spelling of 5206721221 in words is "five billion, two hundred six million, seven hundred twenty-one thousand, two hundred twenty-one".