216543631 has 2 divisors, whose sum is σ = 216543632. Its totient is φ = 216543630.

The previous prime is 216543619. The next prime is 216543659. The reversal of 216543631 is 136345612.

216543631 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 216543631 - 2⁵ = 216543599 is a prime.

It is a super-2 number, since 2×216543631² = 93782288253328322, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 216543593 and 216543602.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (216543601) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 108271815 + 108271816.

It is an arithmetic number, because the mean of its divisors is an integer number (108271816).

Almost surely, 2^216543631 is an apocalyptic number.

216543631 is a deficient number, since it is larger than the sum of its proper divisors (1).

216543631 is an equidigital number, since it uses as much as digits as its factorization.

216543631 is an evil number, because the sum of its binary digits is even.

The product of its digits is 12960, while the sum is 31.

The square root of 216543631 is about 14715.4215366057. The cubic root of 216543631 is about 600.5029403376.

It can be divided in two parts, 2165 and 43631, that added together give a square (45796 = 214²).

The spelling of 216543631 in words is "two hundred sixteen million, five hundred forty-three thousand, six hundred thirty-one".