215680643 has 2 divisors, whose sum is σ = 215680644. Its totient is φ = 215680642.

The previous prime is 215680639. The next prime is 215680651. The reversal of 215680643 is 346086512.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 215680643 - 2² = 215680639 is a prime.

It is not a weakly prime, because it can be changed into another prime (215688643) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 107840321 + 107840322.

It is an arithmetic number, because the mean of its divisors is an integer number (107840322).

Almost surely, 2^215680643 is an apocalyptic number.

215680643 is a deficient number, since it is larger than the sum of its proper divisors (1).

215680643 is an equidigital number, since it uses as much as digits as its factorization.

215680643 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 34560, while the sum is 35.

The square root of 215680643 is about 14686.0696920585. The cubic root of 215680643 is about 599.7041532225.

The spelling of 215680643 in words is "two hundred fifteen million, six hundred eighty thousand, six hundred forty-three".