81890789621760 has 1632 divisors, whose sum is σ = 345002695464960. Its totient is φ = 17551916531712.

The previous prime is 81890789621731. The next prime is 81890789621761. The reversal of 81890789621760 is 6712698709818.

It is a super-2 number, since 2×81890789621760² (a number of 29 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (72).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81890789621761) 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 95 ways as a sum of consecutive naturals, for example, 40399993867 + ... + 40399995893.

Almost surely, 2^{81890789621760} is an apocalyptic number.

81890789621760 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 81890789621760, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (172501347732480).

81890789621760 is an abundant number, since it is smaller than the sum of its proper divisors (263111905843200).

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

81890789621760 is a wasteful number, since it uses less digits than its factorization.

81890789621760 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2199 (or 2166 counting only the distinct ones).

The product of its (nonzero) digits is 146313216, while the sum is 72.

The spelling of 81890789621760 in words is "eighty-one trillion, eight hundred ninety billion, seven hundred eighty-nine million, six hundred twenty-one thousand, seven hundred sixty".