81336416 has 96 divisors (see below), whose sum is σ = 199584000. Its totient is φ = 31836672.

The previous prime is 81336407. The next prime is 81336419. The reversal of 81336416 is 61463318.

It is a super-2 number, since 2×81336416² = 13231225135450112, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (32).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81336419) 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, 123095 + ... + 123753.

It is an arithmetic number, because the mean of its divisors is an integer number (2079000).

Almost surely, 2^81336416 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 81336416, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (99792000).

81336416 is an abundant number, since it is smaller than the sum of its proper divisors (118247584).

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

81336416 is a wasteful number, since it uses less digits than its factorization.

81336416 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 724 (or 716 counting only the distinct ones).

The product of its digits is 10368, while the sum is 32.

The square root of 81336416 is about 9018.6704119842. The cubic root of 81336416 is about 433.2730509174.

The spelling of 81336416 in words is "eighty-one million, three hundred thirty-six thousand, four hundred sixteen".