216861812 has 12 divisors (see below), whose sum is σ = 379753920. Its totient is φ = 108360696.

The previous prime is 216861787. The next prime is 216861863. The reversal of 216861812 is 218168612.

216861812 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10268 + ... + 23219.

It is an arithmetic number, because the mean of its divisors is an integer number (31646160).

Almost surely, 2^216861812 is an apocalyptic number.

It is an amenable number.

216861812 is a deficient number, since it is larger than the sum of its proper divisors (162892108).

216861812 is a wasteful number, since it uses less digits than its factorization.

216861812 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 35110 (or 35108 counting only the distinct ones).

The product of its digits is 9216, while the sum is 35.

The square root of 216861812 is about 14726.2287093471. The cubic root of 216861812 is about 600.7969151492.

The spelling of 216861812 in words is "two hundred sixteen million, eight hundred sixty-one thousand, eight hundred twelve".