216705427 has 4 divisors (see below), whose sum is σ = 216743040. Its totient is φ = 216667816.

The previous prime is 216705397. The next prime is 216705449. The reversal of 216705427 is 724507612.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-216705427 is a prime.

It is a super-2 number, since 2×216705427² = 93922484182504658, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 216705392 and 216705401.

It is not an unprimeable number, because it can be changed into a prime (216705457) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8152 + ... + 22357.

It is an arithmetic number, because the mean of its divisors is an integer number (54185760).

Almost surely, 2^216705427 is an apocalyptic number.

216705427 is a deficient number, since it is larger than the sum of its proper divisors (37613).

216705427 is an equidigital number, since it uses as much as digits as its factorization.

216705427 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 37612.

The product of its (nonzero) digits is 23520, while the sum is 34.

The square root of 216705427 is about 14720.9180080591. The cubic root of 216705427 is about 600.6524633769.

The spelling of 216705427 in words is "two hundred sixteen million, seven hundred five thousand, four hundred twenty-seven".