81809713425258 has 384 divisors, whose sum is σ = 230589071032320. Its totient is φ = 20380851832320.

The previous prime is 81809713425247. The next prime is 81809713425283. The reversal of 81809713425258 is 85252431790818.

81809713425258 is a `hidden beast` number, since 8 + 1 + 8 + 0 + 9 + 71 + 34 + 2 + 525 + 8 = 666.

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 = 81809713425195 and 81809713425204.

It is an unprimeable number.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 3456395848 + ... + 3456419516.

It is an arithmetic number, because the mean of its divisors is an integer number (600492372480).

Almost surely, 2^{81809713425258} is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81809713425258, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (115294535516160).

81809713425258 is an abundant number, since it is smaller than the sum of its proper divisors (148779357607062).

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

81809713425258 is a wasteful number, since it uses less digits than its factorization.

81809713425258 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25354 (or 25351 counting only the distinct ones).

The product of its (nonzero) digits is 38707200, while the sum is 63.

The spelling of 81809713425258 in words is "eighty-one trillion, eight hundred nine billion, seven hundred thirteen million, four hundred twenty-five thousand, two hundred fifty-eight".