81188050944 has 768 divisors, whose sum is σ = 298343485440. Its totient is φ = 18951045120.

The previous prime is 81188050921. The next prime is 81188050967. The reversal of 81188050944 is 44905088118.

It is an interprime number because it is at equal distance from previous prime (81188050921) and next prime (81188050967).

It is a tau number, because it is divible by the number of its divisors (768).

It is a super-2 number, since 2×81188050944² (a number of 23 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (48).

It is a junction number, because it is equal to n+sod(n) for n = 81188050893 and 81188050902.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 264456039 + ... + 264456345.

It is an arithmetic number, because the mean of its divisors is an integer number (388468080).

Almost surely, 2^81188050944 is an apocalyptic number.

81188050944 is a gapful number since it is divisible by the number (84) 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 81188050944, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (149171742720).

81188050944 is an abundant number, since it is smaller than the sum of its proper divisors (217155434496).

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

81188050944 is a wasteful number, since it uses less digits than its factorization.

81188050944 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 406 (or 386 counting only the distinct ones).

The product of its (nonzero) digits is 368640, while the sum is 48.

The spelling of 81188050944 in words is "eighty-one billion, one hundred eighty-eight million, fifty thousand, nine hundred forty-four".