81321893001 has 32 divisors (see below), whose sum is σ = 124388490240. Its totient is φ = 52455081600.

The previous prime is 81321892991. The next prime is 81321893047. The reversal of 81321893001 is 10039812318.

It is not a de Polignac number, because 81321893001 - 2¹⁰ = 81321891977 is a prime.

It is a super-2 number, since 2×81321893001² (a number of 23 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (81321894001) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 7880221 + ... + 7890533.

It is an arithmetic number, because the mean of its divisors is an integer number (3887140320).

Almost surely, 2^81321893001 is an apocalyptic number.

It is an amenable number.

81321893001 is a deficient number, since it is larger than the sum of its proper divisors (43066597239).

81321893001 is a wasteful number, since it uses less digits than its factorization.

81321893001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19774 (or 19768 counting only the distinct ones).

The product of its (nonzero) digits is 10368, while the sum is 36.

The spelling of 81321893001 in words is "eighty-one billion, three hundred twenty-one million, eight hundred ninety-three thousand, one".