20839919 has 2 divisors, whose sum is σ = 20839920. Its totient is φ = 20839918.

The previous prime is 20839913. The next prime is 20839927. The reversal of 20839919 is 91993802.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20839919 is a prime.

It is a super-2 number, since 2×20839919² = 868604447853122, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20839913) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10419959 + 10419960.

It is an arithmetic number, because the mean of its divisors is an integer number (10419960).

Almost surely, 2^20839919 is an apocalyptic number.

20839919 is a deficient number, since it is larger than the sum of its proper divisors (1).

20839919 is an equidigital number, since it uses as much as digits as its factorization.

20839919 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 34992, while the sum is 41.

The square root of 20839919 is about 4565.0760125106. The cubic root of 20839919 is about 275.1895948763.

The spelling of 20839919 in words is "twenty million, eight hundred thirty-nine thousand, nine hundred nineteen".