81326268 has 72 divisors (see below), whose sum is σ = 220147200. Its totient is φ = 26224560.

The previous prime is 81326263. The next prime is 81326279. The reversal of 81326268 is 86262318.

It is a super-2 number, since 2×81326268² = 13227923733615648, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81326261) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 28783 + ... + 31481.

It is an arithmetic number, because the mean of its divisors is an integer number (3057600).

Almost surely, 2^81326268 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81326268, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (110073600).

81326268 is an abundant number, since it is smaller than the sum of its proper divisors (138820932).

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

81326268 is a wasteful number, since it uses less digits than its factorization.

81326268 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2749 (or 2735 counting only the distinct ones).

The product of its digits is 27648, while the sum is 36.

The square root of 81326268 is about 9018.1077837870. The cubic root of 81326268 is about 433.2550309537.

It can be divided in two parts, 8132 and 6268, that added together give a square (14400 = 120²).

The spelling of 81326268 in words is "eighty-one million, three hundred twenty-six thousand, two hundred sixty-eight".