81783406080 has 400 divisors, whose sum is σ = 294999645600. Its totient is φ = 21654355968.

The previous prime is 81783406037. The next prime is 81783406087. The reversal of 81783406080 is 8060438718.

81783406080 is a `hidden beast` number, since 8 + 1 + 7 + 8 + 34 + 0 + 608 + 0 = 666.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81783406087) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 30895317 + ... + 30897963.

It is an arithmetic number, because the mean of its divisors is an integer number (737499114).

Almost surely, 2^81783406080 is an apocalyptic number.

81783406080 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 81783406080, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (147499822800).

81783406080 is an abundant number, since it is smaller than the sum of its proper divisors (213216239520).

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

81783406080 is a wasteful number, since it uses less digits than its factorization.

81783406080 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2831 (or 2806 counting only the distinct ones).

The product of its (nonzero) digits is 258048, while the sum is 45.

The spelling of 81783406080 in words is "eighty-one billion, seven hundred eighty-three million, four hundred six thousand, eighty".