215948878209 has 27 divisors (see below), whose sum is σ = 313954949217. Its totient is φ = 143035583400.

The previous prime is 215948878207. The next prime is 215948878231. The reversal of 215948878209 is 902878849512.

The square root of 215948878209 is 464703.

It is a perfect power (a square), and thus also a powerful number.

215948878209 is a `hidden beast` number, since 21 + 59 + 488 + 7 + 82 + 0 + 9 = 666.

It is not a de Polignac number, because 215948878209 - 2¹ = 215948878207 is a prime.

It is a super-3 number, since 3×215948878209³ (a number of 35 digits) contains 333 as substring.

It is not an unprimeable number, because it can be changed into a prime (215948878207) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 266274414 + ... + 266275224.

Almost surely, 2^215948878209 is an apocalyptic number.

215948878209 is the 464703-rd square number.

215948878209 is the 232352-nd centered octagonal number.

It is an amenable number.

215948878209 is a deficient number, since it is larger than the sum of its proper divisors (98006071008).

215948878209 is an frugal number, since it uses more digits than its factorization.

215948878209 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2010 (or 1005 counting only the distinct ones).

The product of its (nonzero) digits is 23224320, while the sum is 63.

The spelling of 215948878209 in words is "two hundred fifteen billion, nine hundred forty-eight million, eight hundred seventy-eight thousand, two hundred nine".