81630431190 has 768 divisors, whose sum is σ = 293417220096. Its totient is φ = 15228518400.

The previous prime is 81630431167. The next prime is 81630431221. The reversal of 81630431190 is 9113403618.

81630431190 is a `hidden beast` number, since 8 + 1 + 6 + 30 + 431 + 190 = 666.

It is a super-2 number, since 2×81630431190² (a number of 23 digits) contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 383 ways as a sum of consecutive naturals, for example, 265897017 + ... + 265897323.

It is an arithmetic number, because the mean of its divisors is an integer number (382053672).

Almost surely, 2^81630431190 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81630431190, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (146708610048).

81630431190 is an abundant number, since it is smaller than the sum of its proper divisors (211786788906).

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

81630431190 is a wasteful number, since it uses less digits than its factorization.

81630431190 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 453 (or 450 counting only the distinct ones).

The product of its (nonzero) digits is 15552, while the sum is 36.

The spelling of 81630431190 in words is "eighty-one billion, six hundred thirty million, four hundred thirty-one thousand, one hundred ninety".