19755058921 has 4 divisors (see below), whose sum is σ = 21274678852. Its totient is φ = 18235438992.

The previous prime is 19755058919. The next prime is 19755058937. The reversal of 19755058921 is 12985055791.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 12985055791 = 19 ⋅683423989.

It can be written as a sum of positive squares in 2 ways, for example, as 12822165225 + 6932893696 = 113235^2 + 83264^2 .

It is a cyclic number.

It is not a de Polignac number, because 19755058921 - 2¹ = 19755058919 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (19755058901) 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, 759809946 + ... + 759809971.

It is an arithmetic number, because the mean of its divisors is an integer number (5318669713).

Almost surely, 2^19755058921 is an apocalyptic number.

It is an amenable number.

19755058921 is a deficient number, since it is larger than the sum of its proper divisors (1519619931).

19755058921 is a wasteful number, since it uses less digits than its factorization.

19755058921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1519619930.

The product of its (nonzero) digits is 1134000, while the sum is 52.

The spelling of 19755058921 in words is "nineteen billion, seven hundred fifty-five million, fifty-eight thousand, nine hundred twenty-one".