216997453 has 2 divisors, whose sum is σ = 216997454. Its totient is φ = 216997452.

The previous prime is 216997411. The next prime is 216997471. The reversal of 216997453 is 354799612.

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., 122168809 + 94828644 = 11053^2 + 9738^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-216997453 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (216997553) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 108498726 + 108498727.

It is an arithmetic number, because the mean of its divisors is an integer number (108498727).

Almost surely, 2^216997453 is an apocalyptic number.

It is an amenable number.

216997453 is a deficient number, since it is larger than the sum of its proper divisors (1).

216997453 is an equidigital number, since it uses as much as digits as its factorization.

216997453 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 408240, while the sum is 46.

The square root of 216997453 is about 14730.8334115894. The cubic root of 216997453 is about 600.9221496000.

The spelling of 216997453 in words is "two hundred sixteen million, nine hundred ninety-seven thousand, four hundred fifty-three".