81698328 has 128 divisors (see below), whose sum is σ = 253152000. Its totient is φ = 24261120.

The previous prime is 81698327. The next prime is 81698333. The reversal of 81698328 is 82389618.

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81698327) 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, 69183 + ... + 70353.

It is an arithmetic number, because the mean of its divisors is an integer number (1977750).

Almost surely, 2^81698328 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 81698328, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (126576000).

81698328 is an abundant number, since it is smaller than the sum of its proper divisors (171453672).

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

81698328 is a wasteful number, since it uses less digits than its factorization.

81698328 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1222 (or 1212 counting only the distinct ones).

The product of its digits is 165888, while the sum is 45.

The square root of 81698328 is about 9038.7127402081. The cubic root of 81698328 is about 433.9147262506.

The spelling of 81698328 in words is "eighty-one million, six hundred ninety-eight thousand, three hundred twenty-eight".