8198153721 has 16 divisors (see below), whose sum is σ = 12148758720. Its totient is φ = 5463930240.

The previous prime is 8198153651. The next prime is 8198153723. The reversal of 8198153721 is 1273518918.

8198153721 is a `hidden beast` number, since 8 + 1 + 98 + 1 + 537 + 21 = 666.

It is not a de Polignac number, because 8198153721 - 2²¹ = 8196056569 is a prime.

It is a super-2 number, since 2×8198153721² (a number of 21 digits) contains 22 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (8198153723) 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, 62761 + ... + 142601.

It is an arithmetic number, because the mean of its divisors is an integer number (759297420).

Almost surely, 2^8198153721 is an apocalyptic number.

It is an amenable number.

8198153721 is a deficient number, since it is larger than the sum of its proper divisors (3950604999).

8198153721 is a wasteful number, since it uses less digits than its factorization.

8198153721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 83653 (or 83647 counting only the distinct ones).

The product of its digits is 120960, while the sum is 45.

The square root of 8198153721 is about 90543.6564371022. The cubic root of 8198153721 is about 2016.3783192892.

The spelling of 8198153721 in words is "eight billion, one hundred ninety-eight million, one hundred fifty-three thousand, seven hundred twenty-one".