81525980 has 12 divisors (see below), whose sum is σ = 171204600. Its totient is φ = 32610384.

The previous prime is 81525973. The next prime is 81526009. The reversal of 81525980 is 8952518.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2038130 + ... + 2038169.

It is an arithmetic number, because the mean of its divisors is an integer number (14267050).

Almost surely, 2^81525980 is an apocalyptic number.

It is an amenable number.

81525980 is an abundant number, since it is smaller than the sum of its proper divisors (89678620).

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

81525980 is a wasteful number, since it uses less digits than its factorization.

81525980 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4076308 (or 4076306 counting only the distinct ones).

The product of its (nonzero) digits is 28800, while the sum is 38.

The square root of 81525980 is about 9029.1738271007. The cubic root of 81525980 is about 433.6093875479.

The spelling of 81525980 in words is "eighty-one million, five hundred twenty-five thousand, nine hundred eighty".