81302078 has 48 divisors (see below), whose sum is σ = 147961968. Its totient is φ = 33264000.

The previous prime is 81302077. The next prime is 81302087. The reversal of 81302078 is 87020318.

It is a super-2 number, since 2×81302078² = 13220055774236168, 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 81302078.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81302077) 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 23 ways as a sum of consecutive naturals, for example, 134978 + ... + 135578.

It is an arithmetic number, because the mean of its divisors is an integer number (3082541).

Almost surely, 2^81302078 is an apocalyptic number.

81302078 is a deficient number, since it is larger than the sum of its proper divisors (66659890).

81302078 is a wasteful number, since it uses less digits than its factorization.

81302078 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 681 (or 670 counting only the distinct ones).

The product of its (nonzero) digits is 2688, while the sum is 29.

The square root of 81302078 is about 9016.7664935940. The cubic root of 81302078 is about 433.2120703427.

The spelling of 81302078 in words is "eighty-one million, three hundred two thousand, seventy-eight".