218151643 has 2 divisors, whose sum is σ = 218151644. Its totient is φ = 218151642.

The previous prime is 218151541. The next prime is 218151653. The reversal of 218151643 is 346151812.

218151643 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-218151643 is a prime.

It is not a weakly prime, because it can be changed into another prime (218151653) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 109075821 + 109075822.

It is an arithmetic number, because the mean of its divisors is an integer number (109075822).

Almost surely, 2^218151643 is an apocalyptic number.

218151643 is a deficient number, since it is larger than the sum of its proper divisors (1).

218151643 is an equidigital number, since it uses as much as digits as its factorization.

218151643 is an evil number, because the sum of its binary digits is even.

The product of its digits is 5760, while the sum is 31.

The square root of 218151643 is about 14769.9574474675. The cubic root of 218151643 is about 601.9856832245.

It can be divided in two parts, 2181 and 51643, that added together give a square (53824 = 232²).

The spelling of 218151643 in words is "two hundred eighteen million, one hundred fifty-one thousand, six hundred forty-three".