81338760 has 48 divisors (see below), whose sum is σ = 264352140. Its totient is φ = 21690240.

The previous prime is 81338759. The next prime is 81338767. The reversal of 81338760 is 6783318.

It can be written as a sum of positive squares in 2 ways, for example, as 78960996 + 2377764 = 8886^2 + 1542^2 .

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

It is not an unprimeable number, because it can be changed into a prime (81338767) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 112611 + ... + 113330.

Almost surely, 2^81338760 is an apocalyptic number.

It is an amenable number.

81338760 is an abundant number, since it is smaller than the sum of its proper divisors (183013380).

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

81338760 is a wasteful number, since it uses less digits than its factorization.

81338760 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 225958 (or 225951 counting only the distinct ones).

The product of its (nonzero) digits is 24192, while the sum is 36.

The square root of 81338760 is about 9018.8003636847. The cubic root of 81338760 is about 433.2772129821.

The spelling of 81338760 in words is "eighty-one million, three hundred thirty-eight thousand, seven hundred sixty".