216851988489658 has 32 divisors (see below), whose sum is σ = 332175915162000. Its totient is φ = 106143858501120.

The previous prime is 216851988489629. The next prime is 216851988489659. The reversal of 216851988489658 is 856984889158612.

It can be written as a sum of positive squares in 8 ways, for example, as 126412402028929 + 90439586460729 = 11243327^2 + 9509973^2 .

It is not an unprimeable number, because it can be changed into a prime (216851988489659) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 74820688 + ... + 77664916.

Almost surely, 2^{216851988489658} is an apocalyptic number.

216851988489658 is a deficient number, since it is larger than the sum of its proper divisors (115323926672342).

216851988489658 is a wasteful number, since it uses less digits than its factorization.

216851988489658 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2847250.

The product of its digits is 19110297600, while the sum is 88.

The spelling of 216851988489658 in words is "two hundred sixteen trillion, eight hundred fifty-one billion, nine hundred eighty-eight million, four hundred eighty-nine thousand, six hundred fifty-eight".