16991420543 has 4 divisors (see below), whose sum is σ = 16999351488. Its totient is φ = 16983489600.

The previous prime is 16991420527. The next prime is 16991420597. The reversal of 16991420543 is 34502419961.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 16991420543 - 2⁴ = 16991420527 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 16991420494 and 16991420503.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16991420843) 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, 3962258 + ... + 3966543.

It is an arithmetic number, because the mean of its divisors is an integer number (4249837872).

Almost surely, 2^16991420543 is an apocalyptic number.

16991420543 is a deficient number, since it is larger than the sum of its proper divisors (7930945).

16991420543 is an equidigital number, since it uses as much as digits as its factorization.

16991420543 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7930944.

The product of its (nonzero) digits is 233280, while the sum is 44.

The spelling of 16991420543 in words is "sixteen billion, nine hundred ninety-one million, four hundred twenty thousand, five hundred forty-three".