216447331 has 2 divisors, whose sum is σ = 216447332. Its totient is φ = 216447330.

The previous prime is 216447311. The next prime is 216447347. The reversal of 216447331 is 133744612.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 216447331 - 2²⁷ = 82229603 is a prime.

It is a super-2 number, since 2×216447331² = 93698894194047122, which contains 22 as substring.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 216447293 and 216447302.

It is not a weakly prime, because it can be changed into another prime (216447311) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 108223665 + 108223666.

It is an arithmetic number, because the mean of its divisors is an integer number (108223666).

Almost surely, 2^216447331 is an apocalyptic number.

216447331 is a deficient number, since it is larger than the sum of its proper divisors (1).

216447331 is an equidigital number, since it uses as much as digits as its factorization.

216447331 is an evil number, because the sum of its binary digits is even.

The product of its digits is 12096, while the sum is 31.

The square root of 216447331 is about 14712.1490952206. The cubic root of 216447331 is about 600.4139097692.

The spelling of 216447331 in words is "two hundred sixteen million, four hundred forty-seven thousand, three hundred thirty-one".