215551085 has 16 divisors (see below), whose sum is σ = 267072816. Its totient is φ = 166883328.

The previous prime is 215551081. The next prime is 215551099. The reversal of 215551085 is 580155512.

215551085 = 10381² + 10382².

215551085 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 8 ways, for example, as 4313929 + 211237156 = 2077^2 + 14534^2 .

It is a cyclic number.

It is not a de Polignac number, because 215551085 - 2² = 215551081 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (215551081) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 32687 + ... + 38723.

It is an arithmetic number, because the mean of its divisors is an integer number (16692051).

Almost surely, 2^215551085 is an apocalyptic number.

215551085 is the 10382-nd centered square number.

It is an amenable number.

215551085 is a deficient number, since it is larger than the sum of its proper divisors (51521731).

215551085 is a wasteful number, since it uses less digits than its factorization.

215551085 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6272.

The product of its (nonzero) digits is 10000, while the sum is 32.

The square root of 215551085 is about 14681.6581148043. The cubic root of 215551085 is about 599.5840496718.

The spelling of 215551085 in words is "two hundred fifteen million, five hundred fifty-one thousand, eighty-five".