81627540 has 96 divisors (see below), whose sum is σ = 245306880. Its totient is φ = 20207616.

The previous prime is 81627509. The next prime is 81627563. The reversal of 81627540 is 4572618.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 80074 + ... + 81086.

It is an arithmetic number, because the mean of its divisors is an integer number (2555280).

Almost surely, 2^81627540 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 81627540, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (122653440).

81627540 is an abundant number, since it is smaller than the sum of its proper divisors (163679340).

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

81627540 is a wasteful number, since it uses less digits than its factorization.

81627540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1121 (or 1119 counting only the distinct ones).

The product of its (nonzero) digits is 13440, while the sum is 33.

The square root of 81627540 is about 9034.7960685341. The cubic root of 81627540 is about 433.7893673765.

The spelling of 81627540 in words is "eighty-one million, six hundred twenty-seven thousand, five hundred forty".