216820783 has 4 divisors (see below), whose sum is σ = 217315120. Its totient is φ = 216326448.

The previous prime is 216820781. The next prime is 216820819. The reversal of 216820783 is 387028612.

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 216820783 - 2¹ = 216820781 is a prime.

It is a super-2 number, since 2×216820783² = 94022503881466178, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (216820781) 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, 246510 + ... + 247387.

It is an arithmetic number, because the mean of its divisors is an integer number (54328780).

Almost surely, 2^216820783 is an apocalyptic number.

216820783 is a deficient number, since it is larger than the sum of its proper divisors (494337).

216820783 is an equidigital number, since it uses as much as digits as its factorization.

216820783 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 494336.

The product of its (nonzero) digits is 32256, while the sum is 37.

The square root of 216820783 is about 14724.8355848206. The cubic root of 216820783 is about 600.7590236595.

The spelling of 216820783 in words is "two hundred sixteen million, eight hundred twenty thousand, seven hundred eighty-three".