16651243 has 4 divisors (see below), whose sum is σ = 19030000. Its totient is φ = 14272488.

The previous prime is 16651237. The next prime is 16651253. The reversal of 16651243 is 34215661.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-16651243 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (16651253) 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, 1189368 + ... + 1189381.

It is an arithmetic number, because the mean of its divisors is an integer number (4757500).

Almost surely, 2^16651243 is an apocalyptic number.

16651243 is a deficient number, since it is larger than the sum of its proper divisors (2378757).

16651243 is an equidigital number, since it uses as much as digits as its factorization.

16651243 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2378756.

The product of its digits is 4320, while the sum is 28.

The square root of 16651243 is about 4080.5934617406. The cubic root of 16651243 is about 255.3576578041.

It can be divided in two parts, 1665 and 1243, that multiplied together give a triangular number (2069595 = T₂₀₃₄).

The spelling of 16651243 in words is "sixteen million, six hundred fifty-one thousand, two hundred forty-three".