216049681553 has 2 divisors, whose sum is σ = 216049681554. Its totient is φ = 216049681552.

The previous prime is 216049681489. The next prime is 216049681579. The reversal of 216049681553 is 355186940612.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 114630999184 + 101418682369 = 338572^2 + 318463^2 .

It is a cyclic number.

It is not a de Polignac number, because 216049681553 - 2⁶ = 216049681489 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (216049689553) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 108024840776 + 108024840777.

It is an arithmetic number, because the mean of its divisors is an integer number (108024840777).

Almost surely, 2^216049681553 is an apocalyptic number.

It is an amenable number.

216049681553 is a deficient number, since it is larger than the sum of its proper divisors (1).

216049681553 is an equidigital number, since it uses as much as digits as its factorization.

216049681553 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1555200, while the sum is 50.

The spelling of 216049681553 in words is "two hundred sixteen billion, forty-nine million, six hundred eighty-one thousand, five hundred fifty-three".