216623537 has 8 divisors (see below), whose sum is σ = 247009896. Its totient is φ = 188197632.

The previous prime is 216623531. The next prime is 216623557. The reversal of 216623537 is 735326612.

It can be written as a sum of positive squares in 4 ways, for example, as 47389456 + 169234081 = 6884^2 + 13009^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 216623537 - 2¹⁸ = 216361393 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 216623497 and 216623506.

It is not an unprimeable number, because it can be changed into a prime (216623531) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 489878 + ... + 490319.

It is an arithmetic number, because the mean of its divisors is an integer number (30876237).

Almost surely, 2^216623537 is an apocalyptic number.

It is an amenable number.

216623537 is a deficient number, since it is larger than the sum of its proper divisors (30386359).

216623537 is a wasteful number, since it uses less digits than its factorization.

216623537 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 980227.

The product of its digits is 45360, while the sum is 35.

The square root of 216623537 is about 14718.1363290330. The cubic root of 216623537 is about 600.5767944101.

The spelling of 216623537 in words is "two hundred sixteen million, six hundred twenty-three thousand, five hundred thirty-seven".