215251643 has 2 divisors, whose sum is σ = 215251644. Its totient is φ = 215251642.

The previous prime is 215251609. The next prime is 215251649. The reversal of 215251643 is 346152512.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 215251643 - 2²⁴ = 198474427 is a prime.

It is not a weakly prime, because it can be changed into another prime (215251649) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 107625821 + 107625822.

It is an arithmetic number, because the mean of its divisors is an integer number (107625822).

Almost surely, 2^215251643 is an apocalyptic number.

215251643 is a deficient number, since it is larger than the sum of its proper divisors (1).

215251643 is an equidigital number, since it uses as much as digits as its factorization.

215251643 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 7200, while the sum is 29.

The square root of 215251643 is about 14671.4567443046. The cubic root of 215251643 is about 599.3062750705.

The spelling of 215251643 in words is "two hundred fifteen million, two hundred fifty-one thousand, six hundred forty-three".