81458531384 has 32 divisors (see below), whose sum is σ = 155632620000. Its totient is φ = 39963756672.

The previous prime is 81458531369. The next prime is 81458531437. The reversal of 81458531384 is 48313585418.

It is a super-2 number, since 2×81458531384² (a number of 23 digits) contains 22 as substring.

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 7 ways as a sum of consecutive naturals, for example, 363659 + ... + 543290.

It is an arithmetic number, because the mean of its divisors is an integer number (4863519375).

Almost surely, 2^81458531384 is an apocalyptic number.

It is an amenable number.

81458531384 is a deficient number, since it is larger than the sum of its proper divisors (74174088616).

81458531384 is a wasteful number, since it uses less digits than its factorization.

81458531384 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 907167 (or 907163 counting only the distinct ones).

The product of its digits is 1843200, while the sum is 50.

The spelling of 81458531384 in words is "eighty-one billion, four hundred fifty-eight million, five hundred thirty-one thousand, three hundred eighty-four".