8131891725 has 72 divisors (see below), whose sum is σ = 15167591712. Its totient is φ = 4318920000.

The previous prime is 8131891667. The next prime is 8131891727. The reversal of 8131891725 is 5271981318.

It is not a de Polignac number, because 8131891725 - 2¹⁸ = 8131629581 is a prime.

It is a super-2 number, since 2×8131891725² (a number of 21 digits) contains 22 as substring.

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 (8131891727) by changing a digit.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 1522159 + ... + 1527491.

It is an arithmetic number, because the mean of its divisors is an integer number (210660996).

Almost surely, 2^8131891725 is an apocalyptic number.

It is an amenable number.

8131891725 is a deficient number, since it is larger than the sum of its proper divisors (7035699987).

8131891725 is a wasteful number, since it uses less digits than its factorization.

8131891725 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5609 (or 5592 counting only the distinct ones).

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

The square root of 8131891725 is about 90177.0021956818. The cubic root of 8131891725 is about 2010.9311235066.

The spelling of 8131891725 in words is "eight billion, one hundred thirty-one million, eight hundred ninety-one thousand, seven hundred twenty-five".