216421894 has 32 divisors (see below), whose sum is σ = 371357280. Its totient is φ = 93768192.

The previous prime is 216421889. The next prime is 216421897. The reversal of 216421894 is 498124612.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (216421897) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 53884 + ... + 57760.

It is an arithmetic number, because the mean of its divisors is an integer number (11604915).

Almost surely, 2^216421894 is an apocalyptic number.

216421894 is a deficient number, since it is larger than the sum of its proper divisors (154935386).

216421894 is a wasteful number, since it uses less digits than its factorization.

216421894 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4024.

The product of its digits is 27648, while the sum is 37.

The square root of 216421894 is about 14711.2845802126. The cubic root of 216421894 is about 600.3903885322.

The spelling of 216421894 in words is "two hundred sixteen million, four hundred twenty-one thousand, eight hundred ninety-four".