216393643 has 2 divisors, whose sum is σ = 216393644. Its totient is φ = 216393642.

The previous prime is 216393607. The next prime is 216393713. The reversal of 216393643 is 346393612.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 216393643 - 2²¹ = 214296491 is a prime.

It is a super-2 number, since 2×216393643² = 93652417461622898, which contains 22 as substring.

It is equal to p_11934919 and since 216393643 and 11934919 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (216393343) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 108196821 + 108196822.

It is an arithmetic number, because the mean of its divisors is an integer number (108196822).

Almost surely, 2^216393643 is an apocalyptic number.

216393643 is a deficient number, since it is larger than the sum of its proper divisors (1).

216393643 is an equidigital number, since it uses as much as digits as its factorization.

216393643 is an evil number, because the sum of its binary digits is even.

The product of its digits is 69984, while the sum is 37.

The square root of 216393643 is about 14710.3243675998. The cubic root of 216393643 is about 600.3642630685.

The spelling of 216393643 in words is "two hundred sixteen million, three hundred ninety-three thousand, six hundred forty-three".