87789217 has 2 divisors, whose sum is σ = 87789218. Its totient is φ = 87789216.

The previous prime is 87789209. The next prime is 87789223. The reversal of 87789217 is 71298778.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 86044176 + 1745041 = 9276^2 + 1321^2 .

It is a cyclic number.

It is not a de Polignac number, because 87789217 - 2³ = 87789209 is a prime.

It is not a weakly prime, because it can be changed into another prime (87789277) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 43894608 + 43894609.

It is an arithmetic number, because the mean of its divisors is an integer number (43894609).

Almost surely, 2^87789217 is an apocalyptic number.

It is an amenable number.

87789217 is a deficient number, since it is larger than the sum of its proper divisors (1).

87789217 is an equidigital number, since it uses as much as digits as its factorization.

87789217 is an evil number, because the sum of its binary digits is even.

The product of its digits is 395136, while the sum is 49.

The square root of 87789217 is about 9369.5900123751. The cubic root of 87789217 is about 444.4405999505.

The spelling of 87789217 in words is "eighty-seven million, seven hundred eighty-nine thousand, two hundred seventeen".