81513124 has 48 divisors (see below), whose sum is σ = 178569216. Its totient is φ = 31629600.

The previous prime is 81513121. The next prime is 81513137. The reversal of 81513124 is 42131518.

It is not an unprimeable number, because it can be changed into a prime (81513121) 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, 117619 + ... + 118309.

It is an arithmetic number, because the mean of its divisors is an integer number (3720192).

Almost surely, 2^81513124 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 81513124, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (89284608).

81513124 is an abundant number, since it is smaller than the sum of its proper divisors (97056092).

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

81513124 is a wasteful number, since it uses less digits than its factorization.

81513124 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1096 (or 1094 counting only the distinct ones).

The product of its digits is 960, while the sum is 25.

The square root of 81513124 is about 9028.4618845072. The cubic root of 81513124 is about 433.5865940968.

The spelling of 81513124 in words is "eighty-one million, five hundred thirteen thousand, one hundred twenty-four".