81847428 has 48 divisors (see below), whose sum is σ = 206458560. Its totient is φ = 25087104.

The previous prime is 81847427. The next prime is 81847429. The reversal of 81847428 is 82474818.

It is an interprime number because it is at equal distance from previous prime (81847427) and next prime (81847429).

It is a self number, because there is not a number n which added to its sum of digits gives 81847428.

It is not an unprimeable number, because it can be changed into a prime (81847427) 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, 47038 + ... + 48746.

It is an arithmetic number, because the mean of its divisors is an integer number (4301220).

Almost surely, 2^81847428 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 81847428, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (103229280).

81847428 is an abundant number, since it is smaller than the sum of its proper divisors (124611132).

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

81847428 is a wasteful number, since it uses less digits than its factorization.

81847428 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2036 (or 2034 counting only the distinct ones).

The product of its digits is 114688, while the sum is 42.

The square root of 81847428 is about 9046.9568364174. The cubic root of 81847428 is about 434.1785316015.

The spelling of 81847428 in words is "eighty-one million, eight hundred forty-seven thousand, four hundred twenty-eight".