216999553 has 2 divisors, whose sum is σ = 216999554. Its totient is φ = 216999552.

The previous prime is 216999527. The next prime is 216999569. The reversal of 216999553 is 355999612.

216999553 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 182331009 + 34668544 = 13503^2 + 5888^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-216999553 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 216999497 and 216999506.

It is not a weakly prime, because it can be changed into another prime (216999583) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 108499776 + 108499777.

It is an arithmetic number, because the mean of its divisors is an integer number (108499777).

Almost surely, 2^216999553 is an apocalyptic number.

It is an amenable number.

216999553 is a deficient number, since it is larger than the sum of its proper divisors (1).

216999553 is an equidigital number, since it uses as much as digits as its factorization.

216999553 is an evil number, because the sum of its binary digits is even.

The product of its digits is 656100, while the sum is 49.

The square root of 216999553 is about 14730.9046904798. The cubic root of 216999553 is about 600.9240880751.

The spelling of 216999553 in words is "two hundred sixteen million, nine hundred ninety-nine thousand, five hundred fifty-three".