2216720537 has 4 divisors (see below), whose sum is σ = 2217619380. Its totient is φ = 2215821696.

The previous prime is 2216720489. The next prime is 2216720567. The reversal of 2216720537 is 7350276122.

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 1905409801 + 311310736 = 43651^2 + 17644^2 .

It is a cyclic number.

It is not a de Polignac number, because 2216720537 - 2⁸ = 2216720281 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 2216720497 and 2216720506.

It is not an unprimeable number, because it can be changed into a prime (2216720567) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 445712 + ... + 450657.

It is an arithmetic number, because the mean of its divisors is an integer number (554404845).

Almost surely, 2^2216720537 is an apocalyptic number.

It is an amenable number.

2216720537 is a deficient number, since it is larger than the sum of its proper divisors (898843).

2216720537 is an equidigital number, since it uses as much as digits as its factorization.

2216720537 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 898842.

The product of its (nonzero) digits is 35280, while the sum is 35.

The square root of 2216720537 is about 47082.0617326812. The cubic root of 2216720537 is about 1303.8780719628.

Adding to 2216720537 its reverse (7350276122), we get a palindrome (9566996659).

The spelling of 2216720537 in words is "two billion, two hundred sixteen million, seven hundred twenty thousand, five hundred thirty-seven".