217061290 has 16 divisors (see below), whose sum is σ = 391573512. Its totient is φ = 86632704.

The previous prime is 217061267. The next prime is 217061309. The reversal of 217061290 is 92160712.

It is a happy number.

217061290 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Cunningham number, because it is equal to 14733²+1.

It can be written as a sum of positive squares in 4 ways, for example, as 217061289 + 1 = 14733^2 + 1^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 19179 + ... + 28318.

Almost surely, 2^217061290 is an apocalyptic number.

217061290 is a deficient number, since it is larger than the sum of its proper divisors (174512222).

217061290 is a wasteful number, since it uses less digits than its factorization.

217061290 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 47961.

The product of its (nonzero) digits is 1512, while the sum is 28.

The square root of 217061290 is about 14733.0000339374. Note that the first 4 decimals coincide. The cubic root of 217061290 is about 600.9810708848.

The spelling of 217061290 in words is "two hundred seventeen million, sixty-one thousand, two hundred ninety".