20919449 has 2 divisors, whose sum is σ = 20919450. Its totient is φ = 20919448.

The previous prime is 20919433. The next prime is 20919461. The reversal of 20919449 is 94491902.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 13801225 + 7118224 = 3715^2 + 2668^2 .

It is a cyclic number.

It is not a de Polignac number, because 20919449 - 2⁴ = 20919433 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (20919419) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10459724 + 10459725.

It is an arithmetic number, because the mean of its divisors is an integer number (10459725).

Almost surely, 2^20919449 is an apocalyptic number.

It is an amenable number.

20919449 is a deficient number, since it is larger than the sum of its proper divisors (1).

20919449 is an equidigital number, since it uses as much as digits as its factorization.

20919449 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 23328, while the sum is 38.

The square root of 20919449 is about 4573.7784161457. The cubic root of 20919449 is about 275.5392131078.

The spelling of 20919449 in words is "twenty million, nine hundred nineteen thousand, four hundred forty-nine".