216709377 has 4 divisors (see below), whose sum is σ = 288945840. Its totient is φ = 144472916.

The previous prime is 216709357. The next prime is 216709399. The reversal of 216709377 is 773907612.

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 216709377 - 2¹⁰ = 216708353 is a prime.

It is not an unprimeable number, because it can be changed into a prime (216709327) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 36118227 + ... + 36118232.

It is an arithmetic number, because the mean of its divisors is an integer number (72236460).

Almost surely, 2^216709377 is an apocalyptic number.

It is an amenable number.

216709377 is a deficient number, since it is larger than the sum of its proper divisors (72236463).

216709377 is an equidigital number, since it uses as much as digits as its factorization.

216709377 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 72236462.

The product of its (nonzero) digits is 111132, while the sum is 42.

The square root of 216709377 is about 14721.0521702764. The cubic root of 216709377 is about 600.6561128206.

The spelling of 216709377 in words is "two hundred sixteen million, seven hundred nine thousand, three hundred seventy-seven".