19561931023 has 16 divisors (see below), whose sum is σ = 21267671040. Its totient is φ = 17924479200.

The previous prime is 19561931021. The next prime is 19561931087. The reversal of 19561931023 is 32013916591.

It is a cyclic number.

It is not a de Polignac number, because 19561931023 - 2¹ = 19561931021 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19561931021) 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 15 ways as a sum of consecutive naturals, for example, 1167918 + ... + 1184548.

It is an arithmetic number, because the mean of its divisors is an integer number (1329229440).

Almost surely, 2^19561931023 is an apocalyptic number.

19561931023 is a deficient number, since it is larger than the sum of its proper divisors (1705740017).

19561931023 is a wasteful number, since it uses less digits than its factorization.

19561931023 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18678.

The product of its (nonzero) digits is 43740, while the sum is 40.

The spelling of 19561931023 in words is "nineteen billion, five hundred sixty-one million, nine hundred thirty-one thousand, twenty-three".