81373215382 has 4 divisors (see below), whose sum is σ = 122059823076. Its totient is φ = 40686607690.

The previous prime is 81373215337. The next prime is 81373215383. The reversal of 81373215382 is 28351237318.

It is a happy number.

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

It is a super-2 number, since 2×81373215382² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81373215383) by changing a digit.

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 as a sum of consecutive naturals, namely, 20343303844 + ... + 20343303847.

It is an arithmetic number, because the mean of its divisors is an integer number (30514955769).

Almost surely, 2^81373215382 is an apocalyptic number.

81373215382 is a deficient number, since it is larger than the sum of its proper divisors (40686607694).

81373215382 is a wasteful number, since it uses less digits than its factorization.

81373215382 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40686607693.

The product of its digits is 241920, while the sum is 43.

The spelling of 81373215382 in words is "eighty-one billion, three hundred seventy-three million, two hundred fifteen thousand, three hundred eighty-two".