81278734 has 24 divisors (see below), whose sum is σ = 134976240. Its totient is φ = 36577728.

The previous prime is 81278731. The next prime is 81278749. The reversal of 81278734 is 43787218.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81278731) 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, 15727 + ... + 20245.

It is an arithmetic number, because the mean of its divisors is an integer number (5624010).

Almost surely, 2^81278734 is an apocalyptic number.

81278734 is a deficient number, since it is larger than the sum of its proper divisors (53697506).

81278734 is a wasteful number, since it uses less digits than its factorization.

81278734 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4584 (or 4561 counting only the distinct ones).

The product of its digits is 75264, while the sum is 40.

The square root of 81278734 is about 9015.4719233105. The cubic root of 81278734 is about 433.1706041184.

It can be divided in two parts, 8127 and 8734, that added together give a palindrome (16861).

The spelling of 81278734 in words is "eighty-one million, two hundred seventy-eight thousand, seven hundred thirty-four".