216923091 has 16 divisors (see below), whose sum is σ = 360599808. Its totient is φ = 112687200.

The previous prime is 216923081. The next prime is 216923099. The reversal of 216923091 is 190329612.

It is not a de Polignac number, because 216923091 - 2⁵ = 216923059 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is not an unprimeable number, because it can be changed into a prime (216923099) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 469300 + ... + 469761.

It is an arithmetic number, because the mean of its divisors is an integer number (22537488).

Almost surely, 2^216923091 is an apocalyptic number.

216923091 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

216923091 is a deficient number, since it is larger than the sum of its proper divisors (143676717).

216923091 is a wasteful number, since it uses less digits than its factorization.

216923091 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 939082.

The product of its (nonzero) digits is 5832, while the sum is 33.

The square root of 216923091 is about 14728.3091697588. The cubic root of 216923091 is about 600.8534992117.

The spelling of 216923091 in words is "two hundred sixteen million, nine hundred twenty-three thousand, ninety-one".