16573806991 has 16 divisors (see below), whose sum is σ = 20465006400. Its totient is φ = 13370461440.

The previous prime is 16573806917. The next prime is 16573807009. The reversal of 16573806991 is 19960837561.

It is a happy number.

It is not a de Polignac number, because 16573806991 - 2⁹ = 16573806479 is a prime.

It is a Smith number, since the sum of its digits (55) coincides with the sum of the digits of its prime factors.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16573806901) 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, 1415350 + ... + 1427011.

It is an arithmetic number, because the mean of its divisors is an integer number (1279062900).

Almost surely, 2^16573806991 is an apocalyptic number.

16573806991 is a deficient number, since it is larger than the sum of its proper divisors (3891199409).

16573806991 is an equidigital number, since it uses as much as digits as its factorization.

16573806991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2842399 (or 2842385 counting only the distinct ones).

The product of its (nonzero) digits is 2449440, while the sum is 55.

The spelling of 16573806991 in words is "sixteen billion, five hundred seventy-three million, eight hundred six thousand, nine hundred ninety-one".