81385882 has 4 divisors (see below), whose sum is σ = 122078826. Its totient is φ = 40692940.

The previous prime is 81385867. The next prime is 81385921. The reversal of 81385882 is 28858318.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 28858318 = 2 ⋅14429159.

It can be written as a sum of positive squares in only one way, i.e., 47734281 + 33651601 = 6909^2 + 5801^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20346469 + ... + 20346472.

Almost surely, 2^81385882 is an apocalyptic number.

81385882 is a deficient number, since it is larger than the sum of its proper divisors (40692944).

81385882 is a wasteful number, since it uses less digits than its factorization.

81385882 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40692943.

The product of its digits is 122880, while the sum is 43.

The square root of 81385882 is about 9021.4124171329. The cubic root of 81385882 is about 433.3608670210.

The spelling of 81385882 in words is "eighty-one million, three hundred eighty-five thousand, eight hundred eighty-two".