81411200640 has 1536 divisors, whose sum is σ = 371790881280. Its totient is φ = 16057958400.

The previous prime is 81411200597. The next prime is 81411200693. The reversal of 81411200640 is 4600211418.

It is a happy number.

81411200640 is a `hidden beast` number, since 8 + 1 + 4 + 1 + 12 + 0 + 0 + 640 = 666.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 1985639020 + ... + 1985639060.

It is an arithmetic number, because the mean of its divisors is an integer number (242051355).

Almost surely, 2^81411200640 is an apocalyptic number.

81411200640 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 81411200640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (185895440640).

81411200640 is an abundant number, since it is smaller than the sum of its proper divisors (290379680640).

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

81411200640 is a wasteful number, since it uses less digits than its factorization.

81411200640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 143 (or 106 counting only the distinct ones).

The product of its (nonzero) digits is 1536, while the sum is 27.

The spelling of 81411200640 in words is "eighty-one billion, four hundred eleven million, two hundred thousand, six hundred forty".