216284973997 has 2 divisors, whose sum is σ = 216284973998. Its totient is φ = 216284973996.

The previous prime is 216284973941. The next prime is 216284974019. The reversal of 216284973997 is 799379482612.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 158643686601 + 57641287396 = 398301^2 + 240086^2 .

It is a cyclic number.

It is not a de Polignac number, because 216284973997 - 2²³ = 216276585389 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (216284973917) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 108142486998 + 108142486999.

It is an arithmetic number, because the mean of its divisors is an integer number (108142486999).

Almost surely, 2^216284973997 is an apocalyptic number.

It is an amenable number.

216284973997 is a deficient number, since it is larger than the sum of its proper divisors (1).

216284973997 is an equidigital number, since it uses as much as digits as its factorization.

216284973997 is an evil number, because the sum of its binary digits is even.

The product of its digits is 82301184, while the sum is 67.

It can be divided in two parts, 216284 and 973997, that added together give a square (1190281 = 1091²).

The spelling of 216284973997 in words is "two hundred sixteen billion, two hundred eighty-four million, nine hundred seventy-three thousand, nine hundred ninety-seven".