81994710 has 96 divisors (see below), whose sum is σ = 230872320. Its totient is φ = 18255744.

The previous prime is 81994691. The next prime is 81994727. The reversal of 81994710 is 1749918.

It is a happy number.

It is a super-3 number, since 3×81994710³ (a number of 25 digits) contains 333 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 589821 + ... + 589959.

It is an arithmetic number, because the mean of its divisors is an integer number (2404920).

Almost surely, 2^81994710 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81994710, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (115436160).

81994710 is an abundant number, since it is smaller than the sum of its proper divisors (148877610).

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

81994710 is a wasteful number, since it uses less digits than its factorization.

81994710 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 262 (or 209 counting only the distinct ones).

The product of its (nonzero) digits is 18144, while the sum is 39.

The square root of 81994710 is about 9055.0930420399. The cubic root of 81994710 is about 434.4388059747.

The spelling of 81994710 in words is "eighty-one million, nine hundred ninety-four thousand, seven hundred ten".