215681270784 has 176 divisors, whose sum is σ = 657498496128. Its totient is φ = 61575856128.

The previous prime is 215681270773. The next prime is 215681270803. The reversal of 215681270784 is 487072186512.

It is a happy number.

It is a super-2 number, since 2×215681270784² (a number of 23 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 35629102 + ... + 35635154.

Almost surely, 2^215681270784 is an apocalyptic number.

215681270784 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 215681270784, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (328749248064).

215681270784 is an abundant number, since it is smaller than the sum of its proper divisors (441817225344).

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

215681270784 is a wasteful number, since it uses less digits than its factorization.

215681270784 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7740 (or 7722 counting only the distinct ones).

The product of its (nonzero) digits is 1505280, while the sum is 51.

It can be divided in two parts, 21 and 5681270784, that multiplied together give a square (119306686464 = 345408²).

The spelling of 215681270784 in words is "two hundred fifteen billion, six hundred eighty-one million, two hundred seventy thousand, seven hundred eighty-four".