9497987721 has 16 divisors (see below), whose sum is σ = 14240627520. Its totient is φ = 6255701280.

The previous prime is 9497987689. The next prime is 9497987753. The reversal of 9497987721 is 1277897949.

9497987721 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (9497987689) and next prime (9497987753).

It is not a de Polignac number, because 9497987721 - 2⁵ = 9497987689 is a prime.

It is not an unprimeable number, because it can be changed into a prime (9497987021) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2116900 + ... + 2121381.

It is an arithmetic number, because the mean of its divisors is an integer number (890039220).

Almost surely, 2^9497987721 is an apocalyptic number.

It is an amenable number.

9497987721 is a deficient number, since it is larger than the sum of its proper divisors (4742639799).

9497987721 is a wasteful number, since it uses less digits than its factorization.

9497987721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4238373 (or 4238367 counting only the distinct ones).

The product of its digits is 16003008, while the sum is 63.

The square root of 9497987721 is about 97457.6201279305. The cubic root of 9497987721 is about 2117.7622436934.

The spelling of 9497987721 in words is "nine billion, four hundred ninety-seven million, nine hundred eighty-seven thousand, seven hundred twenty-one".