81726520 has 16 divisors (see below), whose sum is σ = 183884760. Its totient is φ = 32690592.

The previous prime is 81726517. The next prime is 81726529. The reversal of 81726520 is 2562718.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81726529) 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 3 ways as a sum of consecutive naturals, for example, 1021542 + ... + 1021621.

Almost surely, 2^81726520 is an apocalyptic number.

It is an amenable number.

81726520 is an abundant number, since it is smaller than the sum of its proper divisors (102158240).

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

81726520 is a wasteful number, since it uses less digits than its factorization.

81726520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2043174 (or 2043170 counting only the distinct ones).

The product of its (nonzero) digits is 6720, while the sum is 31.

The square root of 81726520 is about 9040.2721197982. The cubic root of 81726520 is about 433.9646314626.

The spelling of 81726520 in words is "eighty-one million, seven hundred twenty-six thousand, five hundred twenty".