8121641772 has 48 divisors (see below), whose sum is σ = 19319731200. Its totient is φ = 2654528448.

The previous prime is 8121641771. The next prime is 8121641819. The reversal of 8121641772 is 2771461218.

It is a super-2 number, since 2×8121641772² (a number of 21 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 8121641772.

It is not an unprimeable number, because it can be changed into a prime (8121641771) 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, 1523103 + ... + 1528425.

It is an arithmetic number, because the mean of its divisors is an integer number (402494400).

Almost surely, 2^8121641772 is an apocalyptic number.

It is an amenable number.

8121641772 is an abundant number, since it is smaller than the sum of its proper divisors (11198089428).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

8121641772 is a wasteful number, since it uses less digits than its factorization.

8121641772 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7782 (or 7780 counting only the distinct ones).

The product of its digits is 37632, while the sum is 39.

The square root of 8121641772 is about 90120.1518640531. The cubic root of 8121641772 is about 2010.0858664835.

The spelling of 8121641772 in words is "eight billion, one hundred twenty-one million, six hundred forty-one thousand, seven hundred seventy-two".