2531606221 has 16 divisors (see below), whose sum is σ = 2706715440. Its totient is φ = 2359526400.

The previous prime is 2531606219. The next prime is 2531606237. The reversal of 2531606221 is 1226061352.

It can be written as a sum of positive squares in 8 ways, for example, as 743162121 + 1788444100 = 27261^2 + 42290^2 .

It is a cyclic number.

It is not a de Polignac number, because 2531606221 - 2¹ = 2531606219 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 2531606221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2531606521) 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 15 ways as a sum of consecutive naturals, for example, 765271 + ... + 768571.

It is an arithmetic number, because the mean of its divisors is an integer number (169169715).

Almost surely, 2^2531606221 is an apocalyptic number.

It is an amenable number.

2531606221 is a deficient number, since it is larger than the sum of its proper divisors (175109219).

2531606221 is a wasteful number, since it uses less digits than its factorization.

2531606221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3744.

The product of its (nonzero) digits is 4320, while the sum is 28.

The square root of 2531606221 is about 50315.0695219633. The cubic root of 2531606221 is about 1362.9043721453.

Adding to 2531606221 its reverse (1226061352), we get a palindrome (3757667573).

The spelling of 2531606221 in words is "two billion, five hundred thirty-one million, six hundred six thousand, two hundred twenty-one".