19923861 has 4 divisors (see below), whose sum is σ = 26565152. Its totient is φ = 13282572.

The previous prime is 19923859. The next prime is 19923889. The reversal of 19923861 is 16832991.

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 not a de Polignac number, because 19923861 - 2¹ = 19923859 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 (19923811) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3320641 + ... + 3320646.

It is an arithmetic number, because the mean of its divisors is an integer number (6641288).

Almost surely, 2^19923861 is an apocalyptic number.

It is an amenable number.

19923861 is a deficient number, since it is larger than the sum of its proper divisors (6641291).

19923861 is an equidigital number, since it uses as much as digits as its factorization.

19923861 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6641290.

The product of its digits is 23328, while the sum is 39.

The square root of 19923861 is about 4463.6152387947. The cubic root of 19923861 is about 271.0968685534.

The spelling of 19923861 in words is "nineteen million, nine hundred twenty-three thousand, eight hundred sixty-one".