81374958720 has 480 divisors, whose sum is σ = 319449590460. Its totient is φ = 19725742080.

The previous prime is 81374958703. The next prime is 81374958803. The reversal of 81374958720 is 2785947318.

It is a happy number.

81374958720 is a `hidden beast` number, since 8 + 1 + 37 + 4 + 9 + 587 + 20 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 67072712256 + 14302246464 = 258984^2 + 119592^2 .

It is a tau number, because it is divible by the number of its divisors (480).

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

It is an unprimeable number.

It is a polite number, since it can be written in 59 ways as a sum of consecutive naturals, for example, 6266154 + ... + 6279126.

Almost surely, 2^81374958720 is an apocalyptic number.

81374958720 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 81374958720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (159724795230).

81374958720 is an abundant number, since it is smaller than the sum of its proper divisors (238074631740).

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

81374958720 is a wasteful number, since it uses less digits than its factorization.

81374958720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13026 (or 12994 counting only the distinct ones).

The product of its (nonzero) digits is 3386880, while the sum is 54.

The spelling of 81374958720 in words is "eighty-one billion, three hundred seventy-four million, nine hundred fifty-eight thousand, seven hundred twenty".