81643155292 has 48 divisors (see below), whose sum is σ = 150106521600. Its totient is φ = 38780679168.

The previous prime is 81643155281. The next prime is 81643155337. The reversal of 81643155292 is 29255134618.

It is a Harshad number since it is a multiple of its sum of digits (46).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 9207253 + ... + 9216115.

It is an arithmetic number, because the mean of its divisors is an integer number (3127219200).

Almost surely, 2^81643155292 is an apocalyptic number.

It is an amenable number.

81643155292 is a deficient number, since it is larger than the sum of its proper divisors (68463366308).

81643155292 is a wasteful number, since it uses less digits than its factorization.

81643155292 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9562 (or 9560 counting only the distinct ones).

The product of its digits is 518400, while the sum is 46.

The spelling of 81643155292 in words is "eighty-one billion, six hundred forty-three million, one hundred fifty-five thousand, two hundred ninety-two".