81438000 has 240 divisors, whose sum is σ = 306525024. Its totient is φ = 18547200.

The previous prime is 81437987. The next prime is 81438011. The reversal of 81438000 is 83418.

It is a tau number, because it is divible by the number of its divisors (240).

It is a Harshad number since it is a multiple of its sum of digits (24).

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, 293862 + ... + 294138.

Almost surely, 2^81438000 is an apocalyptic number.

81438000 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 81438000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (153262512).

81438000 is an abundant number, since it is smaller than the sum of its proper divisors (225087024).

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

81438000 is a wasteful number, since it uses less digits than its factorization.

81438000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 317 (or 294 counting only the distinct ones).

The product of its (nonzero) digits is 768, while the sum is 24.

The square root of 81438000 is about 9024.3005269107. The cubic root of 81438000 is about 433.4533526858.

The spelling of 81438000 in words is "eighty-one million, four hundred thirty-eight thousand".