16691973 has 4 divisors (see below), whose sum is σ = 22255968. Its totient is φ = 11127980.

The previous prime is 16691963. The next prime is 16692019. The reversal of 16691973 is 37919661.

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 16691973 - 2⁴ = 16691957 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16691903) 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, 2781993 + ... + 2781998.

It is an arithmetic number, because the mean of its divisors is an integer number (5563992).

Almost surely, 2^16691973 is an apocalyptic number.

It is an amenable number.

16691973 is a deficient number, since it is larger than the sum of its proper divisors (5563995).

16691973 is an equidigital number, since it uses as much as digits as its factorization.

16691973 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5563994.

The product of its digits is 61236, while the sum is 42.

The square root of 16691973 is about 4085.5811092181. The cubic root of 16691973 is about 255.5656952989.

The spelling of 16691973 in words is "sixteen million, six hundred ninety-one thousand, nine hundred seventy-three".