216538401798 has 24 divisors (see below), whose sum is σ = 480077388648. Its totient is φ = 70500874752.

The previous prime is 216538401749. The next prime is 216538401809. The reversal of 216538401798 is 897104835612.

216538401798 is a `hidden beast` number, since 2 + 1 + 6 + 538 + 4 + 0 + 17 + 98 = 666.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 139881915 + ... + 139883462.

It is an arithmetic number, because the mean of its divisors is an integer number (20003224527).

It is a 1-persistent number, because it is pandigital, but 2⋅216538401798 = 433076803596 is not.

Almost surely, 2^216538401798 is an apocalyptic number.

216538401798 is an abundant number, since it is smaller than the sum of its proper divisors (263538986850).

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

216538401798 is a wasteful number, since it uses less digits than its factorization.

216538401798 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 279765428 (or 279765425 counting only the distinct ones).

The product of its (nonzero) digits is 2903040, while the sum is 54.

The spelling of 216538401798 in words is "two hundred sixteen billion, five hundred thirty-eight million, four hundred one thousand, seven hundred ninety-eight".