216791166493 has 48 divisors (see below), whose sum is σ = 253132443648. Its totient is φ = 185147424000.

The previous prime is 216791166491. The next prime is 216791166541. The reversal of 216791166493 is 394661197612.

It is not a de Polignac number, because 216791166493 - 2¹ = 216791166491 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (216791166491) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 35694505 + ... + 35700577.

It is an arithmetic number, because the mean of its divisors is an integer number (5273592576).

Almost surely, 2^216791166493 is an apocalyptic number.

216791166493 is a gapful number since it is divisible by the number (23) formed by its first and last digit.

It is an amenable number.

216791166493 is a deficient number, since it is larger than the sum of its proper divisors (36341277155).

216791166493 is a wasteful number, since it uses less digits than its factorization.

216791166493 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6346 (or 6335 counting only the distinct ones).

The product of its digits is 2939328, while the sum is 55.

The spelling of 216791166493 in words is "two hundred sixteen billion, seven hundred ninety-one million, one hundred sixty-six thousand, four hundred ninety-three".