81257148 has 96 divisors (see below), whose sum is σ = 253478400. Its totient is φ = 21990528.

The previous prime is 81257117. The next prime is 81257149. The reversal of 81257148 is 84175218.

81257148 is a `hidden beast` number, since 81 + 2 + 571 + 4 + 8 = 666.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81257149) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 11536 + ... + 17192.

It is an arithmetic number, because the mean of its divisors is an integer number (2640400).

Almost surely, 2^81257148 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 81257148, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (126739200).

81257148 is an abundant number, since it is smaller than the sum of its proper divisors (172221252).

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

81257148 is a wasteful number, since it uses less digits than its factorization.

81257148 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5696 (or 5688 counting only the distinct ones).

The product of its digits is 17920, while the sum is 36.

The square root of 81257148 is about 9014.2746796401. The cubic root of 81257148 is about 433.1322535844.

The spelling of 81257148 in words is "eighty-one million, two hundred fifty-seven thousand, one hundred forty-eight".