216781704 has 32 divisors (see below), whose sum is σ = 602172000. Its totient is φ = 72260496.

The previous prime is 216781703. The next prime is 216781751. The reversal of 216781704 is 407187612.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is not an unprimeable number, because it can be changed into a prime (216781703) 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, 501594 + ... + 502025.

It is an arithmetic number, because the mean of its divisors is an integer number (18817875).

Almost surely, 2^216781704 is an apocalyptic number.

216781704 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

216781704 is an abundant number, since it is smaller than the sum of its proper divisors (385390296).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

216781704 is a wasteful number, since it uses less digits than its factorization.

216781704 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1003634 (or 1003624 counting only the distinct ones).

The product of its (nonzero) digits is 18816, while the sum is 36.

The square root of 216781704 is about 14723.5085492555. The cubic root of 216781704 is about 600.7229286072.

The spelling of 216781704 in words is "two hundred sixteen million, seven hundred eighty-one thousand, seven hundred four".