81238788 has 36 divisors (see below), whose sum is σ = 212961840. Its totient is φ = 27079272.

The previous prime is 81238777. The next prime is 81238789. The reversal of 81238788 is 88783218.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (36).

It is not an unprimeable number, because it can be changed into a prime (81238789) by changing a digit.

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 in 11 ways as a sum of consecutive naturals, for example, 40818 + ... + 42761.

Almost surely, 2^81238788 is an apocalyptic number.

It is an amenable number.

81238788 is an abundant number, since it is smaller than the sum of its proper divisors (131723052).

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

81238788 is a wasteful number, since it uses less digits than its factorization.

81238788 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 83598 (or 83584 counting only the distinct ones).

The product of its digits is 172032, while the sum is 45.

The square root of 81238788 is about 9013.2562373429. The cubic root of 81238788 is about 433.0996291430.

The spelling of 81238788 in words is "eighty-one million, two hundred thirty-eight thousand, seven hundred eighty-eight".