218640733125591 has 64 divisors (see below), whose sum is σ = 358308226418688. Its totient is φ = 115746916405248.

The previous prime is 218640733125553. The next prime is 218640733125611. The reversal of 218640733125591 is 195521337046812.

It is not a de Polignac number, because 218640733125591 - 2³⁰ = 218639659383767 is a prime.

It is a super-2 number, since 2×218640733125591² (a number of 29 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (218640733127591) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 4769145 + ... + 21448221.

It is an arithmetic number, because the mean of its divisors is an integer number (5598566037792).

It is a 1-persistent number, because it is pandigital, but 2⋅218640733125591 = 437281466251182 is not.

Almost surely, 2^{218640733125591} is an apocalyptic number.

218640733125591 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

218640733125591 is a deficient number, since it is larger than the sum of its proper divisors (139667493293097).

218640733125591 is a wasteful number, since it uses less digits than its factorization.

218640733125591 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16679680.

The product of its (nonzero) digits is 10886400, while the sum is 57.

The spelling of 218640733125591 in words is "two hundred eighteen trillion, six hundred forty billion, seven hundred thirty-three million, one hundred twenty-five thousand, five hundred ninety-one".