217896638436 has 45 divisors (see below), whose sum is σ = 569646820281. Its totient is φ = 72629412048.

The previous prime is 217896638429. The next prime is 217896638563. The reversal of 217896638436 is 634836698712.

The square root of 217896638436 is 466794.

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

217896638436 is a `hidden beast` number, since 217 + 8 + 9 + 6 + 6 + 384 + 36 = 666.

It can be written as a sum of positive squares in only one way, i.e., 47869064100 + 170027574336 = 218790^2 + 412344^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 14 ways as a sum of consecutive naturals, for example, 8389326 + ... + 8415258.

Almost surely, 2^217896638436 is an apocalyptic number.

217896638436 is the 466794-th square number.

It is an amenable number.

217896638436 is an abundant number, since it is smaller than the sum of its proper divisors (351750181845).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

217896638436 is an frugal number, since it uses more digits than its factorization.

217896638436 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 51882 (or 25938 counting only the distinct ones).

The product of its digits is 62705664, while the sum is 63.

The spelling of 217896638436 in words is "two hundred seventeen billion, eight hundred ninety-six million, six hundred thirty-eight thousand, four hundred thirty-six".