81400726 has 32 divisors (see below), whose sum is σ = 147184128. Its totient is φ = 33306240.

The previous prime is 81400721. The next prime is 81400729. The reversal of 81400726 is 62700418.

It is a junction number, because it is equal to n+sod(n) for n = 81400694 and 81400703.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81400721) 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 15 ways as a sum of consecutive naturals, for example, 3871 + ... + 13333.

It is an arithmetic number, because the mean of its divisors is an integer number (4599504).

Almost surely, 2^81400726 is an apocalyptic number.

81400726 is a deficient number, since it is larger than the sum of its proper divisors (65783402).

81400726 is a wasteful number, since it uses less digits than its factorization.

81400726 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9516.

The product of its (nonzero) digits is 2688, while the sum is 28.

The square root of 81400726 is about 9022.2350889344. The cubic root of 81400726 is about 433.3872123670.

The spelling of 81400726 in words is "eighty-one million, four hundred thousand, seven hundred twenty-six".