19997841 has 4 divisors (see below), whose sum is σ = 26663792. Its totient is φ = 13331892.

The previous prime is 19997837. The next prime is 19997867. The reversal of 19997841 is 14879991.

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 19997841 - 2² = 19997837 is a prime.

It is a super-2 number, since 2×19997841² = 799827289322562, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (19997041) 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, 3332971 + ... + 3332976.

It is an arithmetic number, because the mean of its divisors is an integer number (6665948).

Almost surely, 2^19997841 is an apocalyptic number.

It is an amenable number.

19997841 is a deficient number, since it is larger than the sum of its proper divisors (6665951).

19997841 is an equidigital number, since it uses as much as digits as its factorization.

19997841 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6665950.

The product of its digits is 163296, while the sum is 48.

The square root of 19997841 is about 4471.8945649467. The cubic root of 19997841 is about 271.4319939286.

The spelling of 19997841 in words is "nineteen million, nine hundred ninety-seven thousand, eight hundred forty-one".