81325881 has 48 divisors (see below), whose sum is σ = 146065920. Its totient is φ = 42456960.

The previous prime is 81325879. The next prime is 81325883. The reversal of 81325881 is 18852318.

81325881 is a nontrivial binomial coefficient, being equal to C(12754, 2).

It is an interprime number because it is at equal distance from previous prime (81325879) and next prime (81325883).

It is not a de Polignac number, because 81325881 - 2¹ = 81325879 is a prime.

It is a super-2 number, since 2×81325881² = 13227797840852322, which contains 22 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (81325883) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 88816 + ... + 89726.

It is an arithmetic number, because the mean of its divisors is an integer number (3043040).

Almost surely, 2^81325881 is an apocalyptic number.

81325881 is the 12753-rd triangular number and also the 6377-th hexagonal number.

It is an amenable number.

81325881 is a deficient number, since it is larger than the sum of its proper divisors (64740039).

81325881 is a wasteful number, since it uses less digits than its factorization.

81325881 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1046 (or 1043 counting only the distinct ones).

The product of its digits is 15360, while the sum is 36.

The square root of 81325881 is about 9018.0863269321. The cubic root of 81325881 is about 433.2543437220.

The spelling of 81325881 in words is "eighty-one million, three hundred twenty-five thousand, eight hundred eighty-one".