81049947192 has 160 divisors (see below), whose sum is σ = 230731221600. Its totient is φ = 26576121600.

The previous prime is 81049947161. The next prime is 81049947193. The reversal of 81049947192 is 29174994018.

81049947192 is a `hidden beast` number, since 81 + 0 + 4 + 9 + 9 + 471 + 92 = 666.

It is a Smith number, since the sum of its digits (54) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81049947193) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 23416342 + ... + 23419802.

It is an arithmetic number, because the mean of its divisors is an integer number (1442070135).

Almost surely, 2^81049947192 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 81049947192, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (115365610800).

81049947192 is an abundant number, since it is smaller than the sum of its proper divisors (149681274408).

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

81049947192 is a wasteful number, since it uses less digits than its factorization.

81049947192 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4059 (or 4046 counting only the distinct ones).

The product of its (nonzero) digits is 1306368, while the sum is 54.

The spelling of 81049947192 in words is "eighty-one billion, forty-nine million, nine hundred forty-seven thousand, one hundred ninety-two".