81240606 has 24 divisors (see below), whose sum is σ = 177670584. Its totient is φ = 26826480.

The previous prime is 81240563. The next prime is 81240613. The reversal of 81240606 is 60604218.

81240606 is a `hidden beast` number, since 8 + 12 + 40 + 606 = 666.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 81240606.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 19165 + ... + 23016.

It is an arithmetic number, because the mean of its divisors is an integer number (7402941).

Almost surely, 2^81240606 is an apocalyptic number.

81240606 is an abundant number, since it is smaller than the sum of its proper divisors (96429978).

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

81240606 is a wasteful number, since it uses less digits than its factorization.

81240606 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 42296 (or 42293 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 27.

The square root of 81240606 is about 9013.3570882330. The cubic root of 81240606 is about 433.1028598217.

The spelling of 81240606 in words is "eighty-one million, two hundred forty thousand, six hundred six".