81007726 has 16 divisors (see below), whose sum is σ = 125445600. Its totient is φ = 39204000.

The previous prime is 81007699. The next prime is 81007727. The reversal of 81007726 is 62770018.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81007727) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 11976 + ... + 17476.

It is an arithmetic number, because the mean of its divisors is an integer number (7840350).

Almost surely, 2^81007726 is an apocalyptic number.

81007726 is a deficient number, since it is larger than the sum of its proper divisors (44437874).

81007726 is a wasteful number, since it uses less digits than its factorization.

81007726 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5739.

The product of its (nonzero) digits is 4704, while the sum is 31.

The square root of 81007726 is about 9000.4292119876. The cubic root of 81007726 is about 432.6886272230.

The spelling of 81007726 in words is "eighty-one million, seven thousand, seven hundred twenty-six".