19794534521 has 4 divisors (see below), whose sum is σ = 19796082000. Its totient is φ = 19792987044.

The previous prime is 19794534517. The next prime is 19794534593. The reversal of 19794534521 is 12543549791.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 12543549791 = 827 ⋅15167533.

It is a cyclic number.

It is not a de Polignac number, because 19794534521 - 2² = 19794534517 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 19794534521.

It is not an unprimeable number, because it can be changed into a prime (19794534421) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 754391 + ... + 780188.

It is an arithmetic number, because the mean of its divisors is an integer number (4949020500).

Almost surely, 2^19794534521 is an apocalyptic number.

It is an amenable number.

19794534521 is a deficient number, since it is larger than the sum of its proper divisors (1547479).

19794534521 is a wasteful number, since it uses less digits than its factorization.

19794534521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1547478.

The product of its digits is 1360800, while the sum is 50.

The spelling of 19794534521 in words is "nineteen billion, seven hundred ninety-four million, five hundred thirty-four thousand, five hundred twenty-one".