216921742 has 16 divisors (see below), whose sum is σ = 329322672. Its totient is φ = 107153280.

The previous prime is 216921737. The next prime is 216921743. The reversal of 216921742 is 247129612.

It is a junction number, because it is equal to n+sod(n) for n = 216921698 and 216921707.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (216921743) 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, 91492 + ... + 93832.

It is an arithmetic number, because the mean of its divisors is an integer number (20582667).

Almost surely, 2^216921742 is an apocalyptic number.

216921742 is a deficient number, since it is larger than the sum of its proper divisors (112400930).

216921742 is a wasteful number, since it uses less digits than its factorization.

216921742 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2883.

The product of its digits is 12096, while the sum is 34.

The square root of 216921742 is about 14728.2633735278. The cubic root of 216921742 is about 600.8522536811.

The spelling of 216921742 in words is "two hundred sixteen million, nine hundred twenty-one thousand, seven hundred forty-two".