81126575772 has 192 divisors, whose sum is σ = 228380705280. Its totient is φ = 22129459200.

The previous prime is 81126575771. The next prime is 81126575807. The reversal of 81126575772 is 27757562118.

It is a Harshad number since it is a multiple of its sum of digits (51).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81126575771) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 4890372 + ... + 4906932.

It is an arithmetic number, because the mean of its divisors is an integer number (1189482840).

Almost surely, 2^81126575772 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81126575772, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (114190352640).

81126575772 is an abundant number, since it is smaller than the sum of its proper divisors (147254129508).

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

81126575772 is a wasteful number, since it uses less digits than its factorization.

81126575772 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16692 (or 16690 counting only the distinct ones).

The product of its digits is 1646400, while the sum is 51.

The spelling of 81126575772 in words is "eighty-one billion, one hundred twenty-six million, five hundred seventy-five thousand, seven hundred seventy-two".