9721947 has 4 divisors (see below), whose sum is σ = 12962600. Its totient is φ = 6481296.

The previous prime is 9721937. The next prime is 9721951. The reversal of 9721947 is 7491279.

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

It is not a de Polignac number, because 9721947 - 2⁶ = 9721883 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (9721927) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1620322 + ... + 1620327.

It is an arithmetic number, because the mean of its divisors is an integer number (3240650).

Almost surely, 2^9721947 is an apocalyptic number.

9721947 is a deficient number, since it is larger than the sum of its proper divisors (3240653).

9721947 is a wasteful number, since it uses less digits than its factorization.

9721947 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3240652.

The product of its digits is 31752, while the sum is 39.

The square root of 9721947 is about 3118.0036882595. The cubic root of 9721947 is about 213.4278468474.

The spelling of 9721947 in words is "nine million, seven hundred twenty-one thousand, nine hundred forty-seven".