81694689048 has 384 divisors, whose sum is σ = 283360896000. Its totient is φ = 21965271552.

The previous prime is 81694689029. The next prime is 81694689059. The reversal of 81694689048 is 84098649618.

81694689048 is a `hidden beast` number, since 8 + 169 + 468 + 9 + 0 + 4 + 8 = 666.

It is a super-2 number, since 2×81694689048² (a number of 23 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (63).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 11331861 + ... + 11339067.

It is an arithmetic number, because the mean of its divisors is an integer number (737919000).

Almost surely, 2^81694689048 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 81694689048, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (141680448000).

81694689048 is an abundant number, since it is smaller than the sum of its proper divisors (201666206952).

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

81694689048 is a wasteful number, since it uses less digits than its factorization.

81694689048 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7266 (or 7236 counting only the distinct ones).

The product of its (nonzero) digits is 23887872, while the sum is 63.

The spelling of 81694689048 in words is "eighty-one billion, six hundred ninety-four million, six hundred eighty-nine thousand, forty-eight".