87940217 has 2 divisors, whose sum is σ = 87940218. Its totient is φ = 87940216.

The previous prime is 87940213. The next prime is 87940241. The reversal of 87940217 is 71204978.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 78570496 + 9369721 = 8864^2 + 3061^2 .

It is a cyclic number.

It is not a de Polignac number, because 87940217 - 2² = 87940213 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (87940213) 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, 43970108 + 43970109.

It is an arithmetic number, because the mean of its divisors is an integer number (43970109).

Almost surely, 2^87940217 is an apocalyptic number.

It is an amenable number.

87940217 is a deficient number, since it is larger than the sum of its proper divisors (1).

87940217 is an equidigital number, since it uses as much as digits as its factorization.

87940217 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 28224, while the sum is 38.

The square root of 87940217 is about 9377.6445336769. The cubic root of 87940217 is about 444.6952709009.

The spelling of 87940217 in words is "eighty-seven million, nine hundred forty thousand, two hundred seventeen".