216007997 has 2 divisors, whose sum is σ = 216007998. Its totient is φ = 216007996.

The previous prime is 216007991. The next prime is 216007999. The reversal of 216007997 is 799700612.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 204318436 + 11689561 = 14294^2 + 3419^2 .

It is a cyclic number.

It is not a de Polignac number, because 216007997 - 2²⁰ = 214959421 is a prime.

Together with 216007999, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (216007991) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 108003998 + 108003999.

It is an arithmetic number, because the mean of its divisors is an integer number (108003999).

Almost surely, 2^216007997 is an apocalyptic number.

It is an amenable number.

216007997 is a deficient number, since it is larger than the sum of its proper divisors (1).

216007997 is an equidigital number, since it uses as much as digits as its factorization.

216007997 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 47628, while the sum is 41.

The square root of 216007997 is about 14697.2105176459. The cubic root of 216007997 is about 600.0074045383.

The spelling of 216007997 in words is "two hundred sixteen million, seven thousand, nine hundred ninety-seven".