19939243 has 4 divisors (see below), whose sum is σ = 20425608. Its totient is φ = 19452880.

The previous prime is 19939237. The next prime is 19939273. The reversal of 19939243 is 34293991.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 34293991 = 821 ⋅41771.

It is a cyclic number.

It is not a de Polignac number, because 19939243 - 2¹⁷ = 19808171 is a prime.

It is a super-2 number, since 2×19939243² = 795146822826098, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 19939196 and 19939205.

It is not an unprimeable number, because it can be changed into a prime (19939273) 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, 243121 + ... + 243202.

It is an arithmetic number, because the mean of its divisors is an integer number (5106402).

Almost surely, 2^19939243 is an apocalyptic number.

19939243 is a deficient number, since it is larger than the sum of its proper divisors (486365).

19939243 is an equidigital number, since it uses as much as digits as its factorization.

19939243 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 486364.

The product of its digits is 52488, while the sum is 40.

The square root of 19939243 is about 4465.3379491367. The cubic root of 19939243 is about 271.1666164026.

It can be divided in two parts, 1993 and 9243, that added together give a square (11236 = 106²).

The spelling of 19939243 in words is "nineteen million, nine hundred thirty-nine thousand, two hundred forty-three".