81382534 has 4 divisors (see below), whose sum is σ = 122073804. Its totient is φ = 40691266.

The previous prime is 81382523. The next prime is 81382541. The reversal of 81382534 is 43528318.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a super-2 number, since 2×81382534² = 13246233680522312, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 81382534.

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 as a sum of consecutive naturals, namely, 20345632 + ... + 20345635.

It is an arithmetic number, because the mean of its divisors is an integer number (30518451).

Almost surely, 2^81382534 is an apocalyptic number.

81382534 is a deficient number, since it is larger than the sum of its proper divisors (40691270).

81382534 is a wasteful number, since it uses less digits than its factorization.

81382534 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40691269.

The product of its digits is 23040, while the sum is 34.

The square root of 81382534 is about 9021.2268566975. The cubic root of 81382534 is about 433.3549244995.

The spelling of 81382534 in words is "eighty-one million, three hundred eighty-two thousand, five hundred thirty-four".