81594305421 has 16 divisors (see below), whose sum is σ = 108913949760. Its totient is φ = 54335473920.

The previous prime is 81594305407. The next prime is 81594305423. The reversal of 81594305421 is 12450349518.

It is not a de Polignac number, because 81594305421 - 2¹⁰ = 81594304397 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81594305423) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 13150906 + ... + 13157108.

It is an arithmetic number, because the mean of its divisors is an integer number (6807121860).

Almost surely, 2^81594305421 is an apocalyptic number.

It is an amenable number.

81594305421 is a deficient number, since it is larger than the sum of its proper divisors (27319644339).

81594305421 is a wasteful number, since it uses less digits than its factorization.

81594305421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10396.

The product of its (nonzero) digits is 172800, while the sum is 42.

The spelling of 81594305421 in words is "eighty-one billion, five hundred ninety-four million, three hundred five thousand, four hundred twenty-one".