21196439 has 4 divisors (see below), whose sum is σ = 23123400. Its totient is φ = 19269480.

The previous prime is 21196423. The next prime is 21196447. The reversal of 21196439 is 93469112.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21196439 - 2⁴ = 21196423 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21196399 and 21196408.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21196939) 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, 963464 + ... + 963485.

It is an arithmetic number, because the mean of its divisors is an integer number (5780850).

Almost surely, 2^21196439 is an apocalyptic number.

21196439 is a deficient number, since it is larger than the sum of its proper divisors (1926961).

21196439 is a wasteful number, since it uses less digits than its factorization.

21196439 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1926960.

The product of its digits is 11664, while the sum is 35.

The square root of 21196439 is about 4603.9590571594. The cubic root of 21196439 is about 276.7500036041.

It can be divided in two parts, 2119 and 6439, that added together give a palindrome (8558).

The spelling of 21196439 in words is "twenty-one million, one hundred ninety-six thousand, four hundred thirty-nine".