21192839 has 2 divisors, whose sum is σ = 21192840. Its totient is φ = 21192838.

The previous prime is 21192833. The next prime is 21192877. The reversal of 21192839 is 93829112.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21192839 - 2⁸ = 21192583 is a prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 21192799 and 21192808.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21192833) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10596419 + 10596420.

It is an arithmetic number, because the mean of its divisors is an integer number (10596420).

Almost surely, 2^21192839 is an apocalyptic number.

21192839 is a deficient number, since it is larger than the sum of its proper divisors (1).

21192839 is an equidigital number, since it uses as much as digits as its factorization.

21192839 is an evil number, because the sum of its binary digits is even.

The product of its digits is 7776, while the sum is 35.

The square root of 21192839 is about 4603.5680727019. The cubic root of 21192839 is about 276.7343349908.

The spelling of 21192839 in words is "twenty-one million, one hundred ninety-two thousand, eight hundred thirty-nine".