215556215556 has 192 divisors, whose sum is σ = 586416402432. Its totient is φ = 60984000000.

The previous prime is 215556215549. The next prime is 215556215569. The reversal of 215556215556 is 655512655512.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 21766206 + ... + 21776106.

It is an arithmetic number, because the mean of its divisors is an integer number (3054252096).

Almost surely, 2^215556215556 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 215556215556, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (293208201216).

215556215556 is an abundant number, since it is smaller than the sum of its proper divisors (370860186876).

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

215556215556 is a wasteful number, since it uses less digits than its factorization.

215556215556 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10114 (or 10112 counting only the distinct ones).

The product of its digits is 2250000, while the sum is 48.

The spelling of 215556215556 in words is "two hundred fifteen billion, five hundred fifty-six million, two hundred fifteen thousand, five hundred fifty-six".