81473730638400 has 315 divisors, whose sum is σ = 299488884339931. Its totient is φ = 21725461647360.

The previous prime is 81473730638387. The next prime is 81473730638401. The reversal of 81473730638400 is 483603737418.

The square root of 81473730638400 is 9026280.

It is a perfect power (a square), and thus also a powerful number.

81473730638400 is a `hidden beast` number, since 8 + 1 + 473 + 7 + 30 + 63 + 84 + 0 + 0 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 4764720614976 + 76709010023424 = 2182824^2 + 8758368^2 .

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81473730638401) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 44 ways as a sum of consecutive naturals, for example, 3249448264 + ... + 3249473336.

Almost surely, 2^{81473730638400} is an apocalyptic number.

81473730638400 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

81473730638400 is the 9026280-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81473730638400

81473730638400 is an abundant number, since it is smaller than the sum of its proper divisors (218015153701531).

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

81473730638400 is an frugal number, since it uses more digits than its factorization.

81473730638400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 50180 (or 25083 counting only the distinct ones).

The product of its (nonzero) digits is 8128512, while the sum is 54.

The spelling of 81473730638400 in words is "eighty-one trillion, four hundred seventy-three billion, seven hundred thirty million, six hundred thirty-eight thousand, four hundred".