216977651 has 8 divisors (see below), whose sum is σ = 239144304. Its totient is φ = 195217920.

The previous prime is 216977641. The next prime is 216977669. The reversal of 216977651 is 156779612.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-216977651 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (216977641) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 100610 + ... + 102743.

It is an arithmetic number, because the mean of its divisors is an integer number (29893038).

Almost surely, 2^216977651 is an apocalyptic number.

216977651 is a deficient number, since it is larger than the sum of its proper divisors (22166653).

216977651 is a wasteful number, since it uses less digits than its factorization.

216977651 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 203461.

The product of its digits is 158760, while the sum is 44.

The square root of 216977651 is about 14730.1612686352. The cubic root of 216977651 is about 600.9038700884.

The spelling of 216977651 in words is "two hundred sixteen million, nine hundred seventy-seven thousand, six hundred fifty-one".