215581517660 has 12 divisors (see below), whose sum is σ = 452721187128. Its totient is φ = 86232607056.

The previous prime is 215581517639. The next prime is 215581517783. The reversal of 215581517660 is 66715185512.

215581517660 is digitally balanced in base 2 and base 3, because in such bases it contains all the possibile digits an equal number of times.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5389537922 + ... + 5389537961.

It is an arithmetic number, because the mean of its divisors is an integer number (37726765594).

Almost surely, 2^215581517660 is an apocalyptic number.

215581517660 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

215581517660 is an abundant number, since it is smaller than the sum of its proper divisors (237139669468).

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

215581517660 is a wasteful number, since it uses less digits than its factorization.

215581517660 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10779075892 (or 10779075890 counting only the distinct ones).

The product of its (nonzero) digits is 504000, while the sum is 47.

The spelling of 215581517660 in words is "two hundred fifteen billion, five hundred eighty-one million, five hundred seventeen thousand, six hundred sixty".