216745811 has 4 divisors (see below), whose sum is σ = 221357472. Its totient is φ = 212134152.

The previous prime is 216745807. The next prime is 216745819. The reversal of 216745811 is 118547612.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 216745811 - 2² = 216745807 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (216745819) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2305760 + ... + 2305853.

It is an arithmetic number, because the mean of its divisors is an integer number (55339368).

Almost surely, 2^216745811 is an apocalyptic number.

216745811 is a deficient number, since it is larger than the sum of its proper divisors (4611661).

216745811 is an equidigital number, since it uses as much as digits as its factorization.

216745811 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4611660.

The product of its digits is 13440, while the sum is 35.

The square root of 216745811 is about 14722.2895977494. The cubic root of 216745811 is about 600.6897724601.

The spelling of 216745811 in words is "two hundred sixteen million, seven hundred forty-five thousand, eight hundred eleven".