216638767 has 8 divisors (see below), whose sum is σ = 219248640. Its totient is φ = 214038840.

The previous prime is 216638753. The next prime is 216638791. The reversal of 216638767 is 767836612.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 216638767 - 2²⁷ = 82421039 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (216638707) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 47142 + ... + 51532.

It is an arithmetic number, because the mean of its divisors is an integer number (27406080).

Almost surely, 2^216638767 is an apocalyptic number.

216638767 is a deficient number, since it is larger than the sum of its proper divisors (2609873).

216638767 is a wasteful number, since it uses less digits than its factorization.

216638767 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4973.

The product of its digits is 508032, while the sum is 46.

The square root of 216638767 is about 14718.6537088145. The cubic root of 216638767 is about 600.5908688582.

The spelling of 216638767 in words is "two hundred sixteen million, six hundred thirty-eight thousand, seven hundred sixty-seven".