81509006 has 8 divisors (see below), whose sum is σ = 122939544. Its totient is φ = 40529160.

The previous prime is 81508991. The next prime is 81509009. The reversal of 81509006 is 60090518.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a self number, because there is not a number n which added to its sum of digits gives 81509006.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81509009) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 112220 + ... + 112943.

It is an arithmetic number, because the mean of its divisors is an integer number (15367443).

Almost surely, 2^81509006 is an apocalyptic number.

81509006 is a deficient number, since it is larger than the sum of its proper divisors (41430538).

81509006 is a wasteful number, since it uses less digits than its factorization.

81509006 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 225346.

The product of its (nonzero) digits is 2160, while the sum is 29.

The square root of 81509006 is about 9028.2338250624. The cubic root of 81509006 is about 433.5792924518.

The spelling of 81509006 in words is "eighty-one million, five hundred nine thousand, six".