81867396870 has 256 divisors, whose sum is σ = 261090754560. Its totient is φ = 17859916800.

The previous prime is 81867396847. The next prime is 81867396883. The reversal of 81867396870 is 7869376818.

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

It is a junction number, because it is equal to n+sod(n) for n = 81867396798 and 81867396807.

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 127 ways as a sum of consecutive naturals, for example, 4267500 + ... + 4286640.

It is an arithmetic number, because the mean of its divisors is an integer number (1019885760).

Almost surely, 2^81867396870 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81867396870, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (130545377280).

81867396870 is an abundant number, since it is smaller than the sum of its proper divisors (179223357690).

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

81867396870 is a wasteful number, since it uses less digits than its factorization.

81867396870 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19268 (or 19262 counting only the distinct ones).

The product of its (nonzero) digits is 24385536, while the sum is 63.

The spelling of 81867396870 in words is "eighty-one billion, eight hundred sixty-seven million, three hundred ninety-six thousand, eight hundred seventy".