90864217 has 4 divisors (see below), whose sum is σ = 90883300. Its totient is φ = 90845136.

The previous prime is 90864211. The next prime is 90864227. The reversal of 90864217 is 71246809.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 71246809 = 383 ⋅186023.

It can be written as a sum of positive squares in 2 ways, for example, as 55115776 + 35748441 = 7424^2 + 5979^2 .

It is a cyclic number.

It is not a de Polignac number, because 90864217 - 2¹¹ = 90862169 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (90864211) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4159 + ... + 14107.

It is an arithmetic number, because the mean of its divisors is an integer number (22720825).

Almost surely, 2^90864217 is an apocalyptic number.

It is an amenable number.

90864217 is a deficient number, since it is larger than the sum of its proper divisors (19083).

90864217 is an equidigital number, since it uses as much as digits as its factorization.

90864217 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19082.

The product of its (nonzero) digits is 24192, while the sum is 37.

The square root of 90864217 is about 9532.2723943454. The cubic root of 90864217 is about 449.5703174201.

The spelling of 90864217 in words is "ninety million, eight hundred sixty-four thousand, two hundred seventeen".