8125399881 has 9 divisors (see below), whose sum is σ = 11737079341. Its totient is φ = 5416752972.

The previous prime is 8125399783. The next prime is 8125399901. The reversal of 8125399881 is 1889935218.

The square root of 8125399881 is 90141.

It is a perfect power (a square), and thus also a powerful number.

8125399881 is a `hidden beast` number, since 8 + 12 + 539 + 98 + 8 + 1 = 666.

It is a tau number, because it is divible by the number of its divisors (9).

It is not a de Polignac number, because 8125399881 - 2⁹ = 8125399369 is a prime.

It is a super-2 number, since 2×8125399881² (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 (8125391881) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 255400 + ... + 285446.

Almost surely, 2^8125399881 is an apocalyptic number.

8125399881 is the 90141-st square number.

8125399881 is the 45071-st centered octagonal number.

It is an amenable number.

8125399881 is a deficient number, since it is larger than the sum of its proper divisors (3611679460).

8125399881 is an frugal number, since it uses more digits than its factorization.

8125399881 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 60100 (or 30050 counting only the distinct ones).

The product of its digits is 1244160, while the sum is 54.

The cubic root of 8125399881 is about 2010.3958595091.

The spelling of 8125399881 in words is "eight billion, one hundred twenty-five million, three hundred ninety-nine thousand, eight hundred eighty-one".