215730649 has 2 divisors, whose sum is σ = 215730650. Its totient is φ = 215730648.

The previous prime is 215730637. The next prime is 215730659. The reversal of 215730649 is 946037512.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 178703424 + 37027225 = 13368^2 + 6085^2 .

It is a cyclic number.

It is not a de Polignac number, because 215730649 - 2¹⁷ = 215599577 is a prime.

It is a super-2 number, since 2×215730649² = 93079425835922402, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (215730659) 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, 107865324 + 107865325.

It is an arithmetic number, because the mean of its divisors is an integer number (107865325).

Almost surely, 2^215730649 is an apocalyptic number.

It is an amenable number.

215730649 is a deficient number, since it is larger than the sum of its proper divisors (1).

215730649 is an equidigital number, since it uses as much as digits as its factorization.

215730649 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 45360, while the sum is 37.

The square root of 215730649 is about 14687.7720910967. The cubic root of 215730649 is about 599.7504971876.

The spelling of 215730649 in words is "two hundred fifteen million, seven hundred thirty thousand, six hundred forty-nine".