216634931 has 2 divisors, whose sum is σ = 216634932. Its totient is φ = 216634930.

The previous prime is 216634921. The next prime is 216634933. The reversal of 216634931 is 139436612.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 216634931 - 2¹⁴ = 216618547 is a prime.

It is a super-2 number, since 2×216634931² = 93861386658749522, which contains 22 as substring.

Together with 216634933, it forms a pair of twin primes.

It is a Chen prime.

It is equal to p_11947436 and since 216634931 and 11947436 have the same sum of digits, it is a Honaker prime.

It is a junction number, because it is equal to n+sod(n) for n = 216634891 and 216634900.

It is not a weakly prime, because it can be changed into another prime (216634933) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 108317465 + 108317466.

It is an arithmetic number, because the mean of its divisors is an integer number (108317466).

Almost surely, 2^216634931 is an apocalyptic number.

216634931 is a deficient number, since it is larger than the sum of its proper divisors (1).

216634931 is an equidigital number, since it uses as much as digits as its factorization.

216634931 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 23328, while the sum is 35.

The square root of 216634931 is about 14718.5233974064. The cubic root of 216634931 is about 600.5873239707.

The spelling of 216634931 in words is "two hundred sixteen million, six hundred thirty-four thousand, nine hundred thirty-one".