81471740 has 24 divisors (see below), whose sum is σ = 195532512. Its totient is φ = 27933120.

The previous prime is 81471739. The next prime is 81471749. The reversal of 81471740 is 4717418.

It is a junction number, because it is equal to n+sod(n) for n = 81471697 and 81471706.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81471749) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 290831 + ... + 291110.

It is an arithmetic number, because the mean of its divisors is an integer number (8147188).

Almost surely, 2^81471740 is an apocalyptic number.

It is an amenable number.

81471740 is an abundant number, since it is smaller than the sum of its proper divisors (114060772).

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

81471740 is a wasteful number, since it uses less digits than its factorization.

81471740 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 581957 (or 581955 counting only the distinct ones).

The product of its (nonzero) digits is 6272, while the sum is 32.

The square root of 81471740 is about 9026.1697302898. The cubic root of 81471740 is about 433.5132047487.

The spelling of 81471740 in words is "eighty-one million, four hundred seventy-one thousand, seven hundred forty".