16543997 has 4 divisors (see below), whose sum is σ = 16560960. Its totient is φ = 16527036.

The previous prime is 16543981. The next prime is 16543999. The reversal of 16543997 is 79934561.

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 16543997 - 2⁴ = 16543981 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 (16543999) 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, 6923 + ... + 9000.

It is an arithmetic number, because the mean of its divisors is an integer number (4140240).

Almost surely, 2^16543997 is an apocalyptic number.

It is an amenable number.

16543997 is a deficient number, since it is larger than the sum of its proper divisors (16963).

16543997 is a wasteful number, since it uses less digits than its factorization.

16543997 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16962.

The product of its digits is 204120, while the sum is 44.

The square root of 16543997 is about 4067.4312532605. The cubic root of 16543997 is about 254.8082474881.

The spelling of 16543997 in words is "sixteen million, five hundred forty-three thousand, nine hundred ninety-seven".