81003110400 has 840 divisors, whose sum is σ = 317095586280. Its totient is φ = 20384317440.

The previous prime is 81003110389. The next prime is 81003110411. The reversal of 81003110400 is 401130018.

It is an interprime number because it is at equal distance from previous prime (81003110389) and next prime (81003110411).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 59 ways as a sum of consecutive naturals, for example, 315187072 + ... + 315187328.

Almost surely, 2^81003110400 is an apocalyptic number.

81003110400 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 81003110400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (158547793140).

81003110400 is an abundant number, since it is smaller than the sum of its proper divisors (236092475880).

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

81003110400 is a wasteful number, since it uses less digits than its factorization.

81003110400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 324 (or 286 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 18.

Adding to 81003110400 its reverse (401130018), we get a palindrome (81404240418).

The spelling of 81003110400 in words is "eighty-one billion, three million, one hundred ten thousand, four hundred".