7216909 has 4 divisors (see below), whose sum is σ = 8247904. Its totient is φ = 6185916.

The previous prime is 7216889. The next prime is 7216919. The reversal of 7216909 is 9096127.

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 7216909 - 2¹¹ = 7214861 is a prime.

It is an alternating number because its digits alternate between odd and even.

7216909 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (7216919) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 515487 + ... + 515500.

It is an arithmetic number, because the mean of its divisors is an integer number (2061976).

Almost surely, 2^7216909 is an apocalyptic number.

It is an amenable number.

7216909 is a deficient number, since it is larger than the sum of its proper divisors (1030995).

7216909 is a wasteful number, since it uses less digits than its factorization.

7216909 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1030994.

The product of its (nonzero) digits is 6804, while the sum is 34.

The square root of 7216909 is about 2686.4305313929. The cubic root of 7216909 is about 193.2489204090.

The spelling of 7216909 in words is "seven million, two hundred sixteen thousand, nine hundred nine".