81018974453693 has 8 divisors (see below), whose sum is σ = 81447846122496. Its totient is φ = 80590151624400.

The previous prime is 81018974453621. The next prime is 81018974453699. The reversal of 81018974453693 is 39635447981018.

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

It is a cyclic number.

It is not a de Polignac number, because 81018974453693 - 2¹⁴ = 81018974437309 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81018974453699) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8880938 + ... + 15521243.

It is an arithmetic number, because the mean of its divisors is an integer number (10180980765312).

Almost surely, 2^{81018974453693} is an apocalyptic number.

It is an amenable number.

81018974453693 is a deficient number, since it is larger than the sum of its proper divisors (428871668803).

81018974453693 is a wasteful number, since it uses less digits than its factorization.

81018974453693 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24419755.

The product of its (nonzero) digits is 156764160, while the sum is 68.

The spelling of 81018974453693 in words is "eighty-one trillion, eighteen billion, nine hundred seventy-four million, four hundred fifty-three thousand, six hundred ninety-three".