81401600 has 216 divisors, whose sum is σ = 243317760. Its totient is φ = 26357760.

The previous prime is 81401599. The next prime is 81401609. The reversal of 81401600 is 610418.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81401609) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1030361 + ... + 1030439.

Almost surely, 2^81401600 is an apocalyptic number.

81401600 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81401600, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (121658880).

81401600 is an abundant number, since it is smaller than the sum of its proper divisors (161916160).

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

81401600 is a wasteful number, since it uses less digits than its factorization.

81401600 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 135 (or 116 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 20.

The square root of 81401600 is about 9022.2835246960. The cubic root of 81401600 is about 433.3887634550.

The spelling of 81401600 in words is "eighty-one million, four hundred one thousand, six hundred".