81258100686 has 24 divisors (see below), whose sum is σ = 201210535344. Its totient is φ = 23216600160.

The previous prime is 81258100621. The next prime is 81258100711. The reversal of 81258100686 is 68600185218.

81258100686 is a `hidden beast` number, since 8 + 1 + 2 + 581 + 0 + 0 + 68 + 6 = 666.

It is a super-2 number, since 2×81258100686² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 322452655 + ... + 322452906.

It is an arithmetic number, because the mean of its divisors is an integer number (8383772306).

Almost surely, 2^81258100686 is an apocalyptic number.

81258100686 is an abundant number, since it is smaller than the sum of its proper divisors (119952434658).

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

81258100686 is a wasteful number, since it uses less digits than its factorization.

81258100686 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 644905576 (or 644905573 counting only the distinct ones).

The product of its (nonzero) digits is 184320, while the sum is 45.

The spelling of 81258100686 in words is "eighty-one billion, two hundred fifty-eight million, one hundred thousand, six hundred eighty-six".