81352780 has 12 divisors (see below), whose sum is σ = 170840880. Its totient is φ = 32541104.

The previous prime is 81352763. The next prime is 81352783. The reversal of 81352780 is 8725318.

It is not an unprimeable number, because it can be changed into a prime (81352783) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2033800 + ... + 2033839.

It is an arithmetic number, because the mean of its divisors is an integer number (14236740).

Almost surely, 2^81352780 is an apocalyptic number.

It is an amenable number.

81352780 is an abundant number, since it is smaller than the sum of its proper divisors (89488100).

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

81352780 is a wasteful number, since it uses less digits than its factorization.

81352780 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4067648 (or 4067646 counting only the distinct ones).

The product of its (nonzero) digits is 13440, while the sum is 34.

The square root of 81352780 is about 9019.5775954310. The cubic root of 81352780 is about 433.3021055735.

The spelling of 81352780 in words is "eighty-one million, three hundred fifty-two thousand, seven hundred eighty".