19894693760621 has 4 divisors (see below), whose sum is σ = 19894756267200. Its totient is φ = 19894631254044.

The previous prime is 19894693760603. The next prime is 19894693760651. The reversal of 19894693760621 is 12606739649891.

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.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-19894693760621 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19894693760651) 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 3 ways as a sum of consecutive naturals, for example, 30773411 + ... + 31413248.

It is an arithmetic number, because the mean of its divisors is an integer number (4973689066800).

Almost surely, 2^{19894693760621} is an apocalyptic number.

It is an amenable number.

19894693760621 is a deficient number, since it is larger than the sum of its proper divisors (62506579).

19894693760621 is an equidigital number, since it uses as much as digits as its factorization.

19894693760621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 62506578.

The product of its (nonzero) digits is 211631616, while the sum is 71.

The spelling of 19894693760621 in words is "nineteen trillion, eight hundred ninety-four billion, six hundred ninety-three million, seven hundred sixty thousand, six hundred twenty-one".