216905100 has 72 divisors (see below), whose sum is σ = 644573328. Its totient is φ = 56275200.

The previous prime is 216905089. The next prime is 216905131. The reversal of 216905100 is 1509612.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1330 + ... + 20870.

Almost surely, 2^216905100 is an apocalyptic number.

216905100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 216905100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (322286664).

216905100 is an abundant number, since it is smaller than the sum of its proper divisors (427668228).

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

216905100 is a wasteful number, since it uses less digits than its factorization.

216905100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19595 (or 19588 counting only the distinct ones).

The product of its (nonzero) digits is 540, while the sum is 24.

The square root of 216905100 is about 14727.6983945218. The cubic root of 216905100 is about 600.8368877111.

The spelling of 216905100 in words is "two hundred sixteen million, nine hundred five thousand, one hundred".