81637401409200 has 1080 divisors, whose sum is σ = 363583882142208. Its totient is φ = 17224570321920.

The previous prime is 81637401409153. The next prime is 81637401409219. The reversal of 81637401409200 is 290410473618.

81637401409200 is a `hidden beast` number, since 8 + 1 + 6 + 37 + 4 + 0 + 1 + 409 + 200 = 666.

It is a tau number, because it is divible by the number of its divisors (1080).

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

It is an unprimeable number.

It is a polite number, since it can be written in 215 ways as a sum of consecutive naturals, for example, 114632617 + ... + 115342583.

Almost surely, 2^{81637401409200} is an apocalyptic number.

81637401409200 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 81637401409200, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (181791941071104).

81637401409200 is an abundant number, since it is smaller than the sum of its proper divisors (281946480733008).

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

81637401409200 is a wasteful number, since it uses less digits than its factorization.

81637401409200 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 710033 (or 709997 counting only the distinct ones).

The product of its (nonzero) digits is 290304, while the sum is 45.

The spelling of 81637401409200 in words is "eighty-one trillion, six hundred thirty-seven billion, four hundred one million, four hundred nine thousand, two hundred".