81185901350400 has 5400 divisors, whose sum is σ = 393767202473568. Its totient is φ = 16452108288000.

The previous prime is 81185901350399. The next prime is 81185901350431. The reversal of 81185901350400 is 405310958118.

81185901350400 is a `hidden beast` number, since 8 + 1 + 1 + 8 + 590 + 1 + 3 + 50 + 4 + 0 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (5400).

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 539 ways as a sum of consecutive naturals, for example, 288917798260 + ... + 288917798540.

Almost surely, 2^{81185901350400} is an apocalyptic number.

81185901350400 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 81185901350400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (196883601236784).

81185901350400 is an abundant number, since it is smaller than the sum of its proper divisors (312581301123168).

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

81185901350400 is a wasteful number, since it uses less digits than its factorization.

81185901350400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 404 (or 356 counting only the distinct ones).

The product of its (nonzero) digits is 172800, while the sum is 45.

The spelling of 81185901350400 in words is "eighty-one trillion, one hundred eighty-five billion, nine hundred one million, three hundred fifty thousand, four hundred".