81938714400 has 864 divisors, whose sum is σ = 317263443840. Its totient is φ = 20401920000.

The previous prime is 81938714327. The next prime is 81938714453. The reversal of 81938714400 is 441783918.

It is a happy number.

81938714400 is a `hidden beast` number, since 81 + 93 + 87 + 1 + 4 + 400 = 666.

It is a tau number, because it is divible by the number of its divisors (864).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 811274350 + ... + 811274450.

It is an arithmetic number, because the mean of its divisors is an integer number (367203060).

Almost surely, 2^81938714400 is an apocalyptic number.

81938714400 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 81938714400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (158631721920).

81938714400 is an abundant number, since it is smaller than the sum of its proper divisors (235324729440).

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

81938714400 is a wasteful number, since it uses less digits than its factorization.

81938714400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 247 (or 205 counting only the distinct ones).

The product of its (nonzero) digits is 193536, while the sum is 45.

The spelling of 81938714400 in words is "eighty-one billion, nine hundred thirty-eight million, seven hundred fourteen thousand, four hundred".