81987126000 has 640 divisors, whose sum is σ = 301372710912. Its totient is φ = 19031040000.

The previous prime is 81987125999. The next prime is 81987126029. The reversal of 81987126000 is 62178918.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 99137587 + ... + 99138413.

Almost surely, 2^81987126000 is an apocalyptic number.

81987126000 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 81987126000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (150686355456).

81987126000 is an abundant number, since it is smaller than the sum of its proper divisors (219385584912).

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

81987126000 is a wasteful number, since it uses less digits than its factorization.

81987126000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 938 (or 922 counting only the distinct ones).

The product of its (nonzero) digits is 48384, while the sum is 42.

The spelling of 81987126000 in words is "eighty-one billion, nine hundred eighty-seven million, one hundred twenty-six thousand".