8721998 has 16 divisors (see below), whose sum is σ = 13471920. Its totient is φ = 4233216.

The previous prime is 8721997. The next prime is 8722001. The reversal of 8721998 is 8991278.

It is a super-2 number, since 2×8721998² = 152146498224008, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (8721997) 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, 10958 + ... + 11726.

It is an arithmetic number, because the mean of its divisors is an integer number (841995).

Almost surely, 2^8721998 is an apocalyptic number.

8721998 is a deficient number, since it is larger than the sum of its proper divisors (4749922).

8721998 is a wasteful number, since it uses less digits than its factorization.

8721998 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 931.

The product of its digits is 72576, while the sum is 44.

The square root of 8721998 is about 2953.3028967581. The cubic root of 8721998 is about 205.8442125010.

The spelling of 8721998 in words is "eight million, seven hundred twenty-one thousand, nine hundred ninety-eight".