8373217721 has 8 divisors (see below), whose sum is σ = 9135734688. Its totient is φ = 7610920000.

The previous prime is 8373217709. The next prime is 8373217739. The reversal of 8373217721 is 1277123738.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 8373217721 - 2¹⁰ = 8373216697 is a prime.

It is a super-2 number, since 2×8373217721² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (8373217751) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 30881 + ... + 133041.

It is an arithmetic number, because the mean of its divisors is an integer number (1141966836).

Almost surely, 2^8373217721 is an apocalyptic number.

It is an amenable number.

8373217721 is a deficient number, since it is larger than the sum of its proper divisors (762516967).

8373217721 is a wasteful number, since it uses less digits than its factorization.

8373217721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 109623.

The product of its digits is 98784, while the sum is 41.

The square root of 8373217721 is about 91505.2879400967. The cubic root of 8373217721 is about 2030.6299840449.

The spelling of 8373217721 in words is "eight billion, three hundred seventy-three million, two hundred seventeen thousand, seven hundred twenty-one".