9934567721 has 16 divisors (see below), whose sum is σ = 11298462336. Its totient is φ = 8665954176.

The previous prime is 9934567717. The next prime is 9934567723. The reversal of 9934567721 is 1277654399.

It is a cyclic number.

It is not a de Polignac number, because 9934567721 - 2² = 9934567717 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (9934567723) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 175340 + ... + 224973.

It is an arithmetic number, because the mean of its divisors is an integer number (706153896).

Almost surely, 2^9934567721 is an apocalyptic number.

It is an amenable number.

9934567721 is a deficient number, since it is larger than the sum of its proper divisors (1363894615).

9934567721 is a wasteful number, since it uses less digits than its factorization.

9934567721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 400432.

The product of its digits is 2857680, while the sum is 53.

The square root of 9934567721 is about 99672.3016740358. The cubic root of 9934567721 is about 2149.7254180437.

The spelling of 9934567721 in words is "nine billion, nine hundred thirty-four million, five hundred sixty-seven thousand, seven hundred twenty-one".