216896906521 has 4 divisors (see below), whose sum is σ = 228312533200. Its totient is φ = 205481279844.

The previous prime is 216896906519. The next prime is 216896906533. The reversal of 216896906521 is 125609698612.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 216896906521 - 2¹ = 216896906519 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (216896906561) 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, 5707813311 + ... + 5707813348.

It is an arithmetic number, because the mean of its divisors is an integer number (57078133300).

Almost surely, 2^216896906521 is an apocalyptic number.

It is an amenable number.

216896906521 is a deficient number, since it is larger than the sum of its proper divisors (11415626679).

216896906521 is a wasteful number, since it uses less digits than its factorization.

216896906521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11415626678.

The product of its (nonzero) digits is 2799360, while the sum is 55.

The spelling of 216896906521 in words is "two hundred sixteen billion, eight hundred ninety-six million, nine hundred six thousand, five hundred twenty-one".