216621199 has 16 divisors (see below), whose sum is σ = 233074368. Its totient is φ = 200800512.

The previous prime is 216621193. The next prime is 216621217. The reversal of 216621199 is 991126612.

216621199 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-216621199 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (37).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (216621193) 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, 388629 + ... + 389185.

It is an arithmetic number, because the mean of its divisors is an integer number (14567148).

Almost surely, 2^216621199 is an apocalyptic number.

216621199 is a deficient number, since it is larger than the sum of its proper divisors (16453169).

216621199 is a wasteful number, since it uses less digits than its factorization.

216621199 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1074.

The product of its digits is 11664, while the sum is 37.

The square root of 216621199 is about 14718.0569030018. The cubic root of 216621199 is about 600.5746337437.

The spelling of 216621199 in words is "two hundred sixteen million, six hundred twenty-one thousand, one hundred ninety-nine".