16621786716493 has 4 divisors (see below), whose sum is σ = 18996327676000. Its totient is φ = 14247245756988.

The previous prime is 16621786716467. The next prime is 16621786716497. The reversal of 16621786716493 is 39461768712661.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 16621786716493 - 2³⁷ = 16484347763021 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 (16621786716497) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1187270479743 + ... + 1187270479756.

It is an arithmetic number, because the mean of its divisors is an integer number (4749081919000).

Almost surely, 2^{16621786716493} is an apocalyptic number.

It is an amenable number.

16621786716493 is a deficient number, since it is larger than the sum of its proper divisors (2374540959507).

16621786716493 is an equidigital number, since it uses as much as digits as its factorization.

16621786716493 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2374540959506.

The product of its digits is 109734912, while the sum is 67.

The spelling of 16621786716493 in words is "sixteen trillion, six hundred twenty-one billion, seven hundred eighty-six million, seven hundred sixteen thousand, four hundred ninety-three".