215663231 has 16 divisors (see below), whose sum is σ = 251424000. Its totient is φ = 181160448.

The previous prime is 215663221. The next prime is 215663233. The reversal of 215663231 is 132366512.

It is a de Polignac number, because none of the positive numbers 2^k-215663231 is a prime.

It is a super-2 number, since 2×215663231² = 93021258410718722, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 215663194 and 215663203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (215663233) 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, 184856 + ... + 186018.

It is an arithmetic number, because the mean of its divisors is an integer number (15714000).

Almost surely, 2^215663231 is an apocalyptic number.

215663231 is a deficient number, since it is larger than the sum of its proper divisors (35760769).

215663231 is a wasteful number, since it uses less digits than its factorization.

215663231 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1678.

The product of its digits is 6480, while the sum is 29.

The square root of 215663231 is about 14685.4768734284. The cubic root of 215663231 is about 599.6880146552.

The spelling of 215663231 in words is "two hundred fifteen million, six hundred sixty-three thousand, two hundred thirty-one".