81701980 has 48 divisors (see below), whose sum is σ = 182891520. Its totient is φ = 30586688.

The previous prime is 81701959. The next prime is 81701987. The reversal of 81701980 is 8910718.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81701987) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 19731 + ... + 23509.

It is an arithmetic number, because the mean of its divisors is an integer number (3810240).

Almost surely, 2^81701980 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 81701980, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (91445760).

81701980 is an abundant number, since it is smaller than the sum of its proper divisors (101189540).

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

81701980 is a wasteful number, since it uses less digits than its factorization.

81701980 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3858 (or 3856 counting only the distinct ones).

The product of its (nonzero) digits is 4032, while the sum is 34.

The square root of 81701980 is about 9038.9147578678. The cubic root of 81701980 is about 433.9211916337.

The spelling of 81701980 in words is "eighty-one million, seven hundred one thousand, nine hundred eighty".