81647244007 has 8 divisors (see below), whose sum is σ = 93339276800. Its totient is φ = 69962246424.

The previous prime is 81647244001. The next prime is 81647244017. The reversal of 81647244007 is 70044274618.

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

It is not a de Polignac number, because 81647244007 - 2³ = 81647243999 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81647244001) 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, 1733907 + ... + 1780372.

It is an arithmetic number, because the mean of its divisors is an integer number (11667409600).

Almost surely, 2^81647244007 is an apocalyptic number.

81647244007 is a deficient number, since it is larger than the sum of its proper divisors (11692032793).

81647244007 is a wasteful number, since it uses less digits than its factorization.

81647244007 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3517605.

The product of its (nonzero) digits is 301056, while the sum is 43.

The spelling of 81647244007 in words is "eighty-one billion, six hundred forty-seven million, two hundred forty-four thousand, seven".