215661017 has 16 divisors (see below), whose sum is σ = 261542400. Its totient is φ = 175132800.

The previous prime is 215661011. The next prime is 215661029. The reversal of 215661017 is 710166512.

It is a cyclic number.

It is not a de Polignac number, because 215661017 - 2¹⁰ = 215659993 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (215661011) 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 in 15 ways as a sum of consecutive naturals, for example, 19892 + ... + 28757.

It is an arithmetic number, because the mean of its divisors is an integer number (16346400).

Almost surely, 2^215661017 is an apocalyptic number.

It is an amenable number.

215661017 is a deficient number, since it is larger than the sum of its proper divisors (45881383).

215661017 is a wasteful number, since it uses less digits than its factorization.

215661017 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 48704.

The product of its (nonzero) digits is 2520, while the sum is 29.

The square root of 215661017 is about 14685.4014926389. The cubic root of 215661017 is about 599.6859625146.

The spelling of 215661017 in words is "two hundred fifteen million, six hundred sixty-one thousand, seventeen".