8181487125 has 144 divisors (see below), whose sum is σ = 17267730480. Its totient is φ = 3715891200.

The previous prime is 8181487121. The next prime is 8181487129. The reversal of 8181487125 is 5217841818.

8181487125 is a `hidden beast` number, since 81 + 81 + 487 + 12 + 5 = 666.

It is an interprime number because it is at equal distance from previous prime (8181487121) and next prime (8181487129).

It can be written as a sum of positive squares in 8 ways, for example, as 4175356689 + 4006130436 = 64617^2 + 63294^2 .

It is not a de Polignac number, because 8181487125 - 2² = 8181487121 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (8181487121) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 10638741 + ... + 10639509.

It is an arithmetic number, because the mean of its divisors is an integer number (119914795).

Almost surely, 2^8181487125 is an apocalyptic number.

It is an amenable number.

8181487125 is an abundant number, since it is smaller than the sum of its proper divisors (9086243355).

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

8181487125 is a wasteful number, since it uses less digits than its factorization.

8181487125 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 997 (or 977 counting only the distinct ones).

The product of its digits is 143360, while the sum is 45.

The square root of 8181487125 is about 90451.5733694003. The cubic root of 8181487125 is about 2015.0109804482.

The spelling of 8181487125 in words is "eight billion, one hundred eighty-one million, four hundred eighty-seven thousand, one hundred twenty-five".