81727380 has 120 divisors (see below), whose sum is σ = 293048448. Its totient is φ = 18677952.

The previous prime is 81727351. The next prime is 81727397. The reversal of 81727380 is 8372718.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 7737 + ... + 14943.

Almost surely, 2^81727380 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 81727380, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (146524224).

81727380 is an abundant number, since it is smaller than the sum of its proper divisors (211321068).

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

81727380 is a wasteful number, since it uses less digits than its factorization.

81727380 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7235 (or 7224 counting only the distinct ones).

The product of its (nonzero) digits is 18816, while the sum is 36.

The square root of 81727380 is about 9040.3196846129. The cubic root of 81727380 is about 433.9661536461.

The spelling of 81727380 in words is "eighty-one million, seven hundred twenty-seven thousand, three hundred eighty".