81447100 has 72 divisors (see below), whose sum is σ = 203181440. Its totient is φ = 27760320.

The previous prime is 81447083. The next prime is 81447131. The reversal of 81447100 is 174418.

It is a super-3 number, since 3×81447100³ (a number of 25 digits) contains 333 as substring.

It is a Harshad number since it is a multiple of its sum of digits (25).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 214711 + ... + 215089.

Almost surely, 2^81447100 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 81447100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (101590720).

81447100 is an abundant number, since it is smaller than the sum of its proper divisors (121734340).

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

81447100 is a wasteful number, since it uses less digits than its factorization.

81447100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 707 (or 700 counting only the distinct ones).

The product of its (nonzero) digits is 896, while the sum is 25.

The square root of 81447100 is about 9024.8047070283. The cubic root of 81447100 is about 433.4694969861.

The spelling of 81447100 in words is "eighty-one million, four hundred forty-seven thousand, one hundred".