20907449 has 2 divisors, whose sum is σ = 20907450. Its totient is φ = 20907448.

The previous prime is 20907421. The next prime is 20907457. The reversal of 20907449 is 94470902.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16362025 + 4545424 = 4045^2 + 2132^2 .

It is a cyclic number.

It is not a de Polignac number, because 20907449 - 2⁸ = 20907193 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (20907409) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10453724 + 10453725.

It is an arithmetic number, because the mean of its divisors is an integer number (10453725).

Almost surely, 2^20907449 is an apocalyptic number.

It is an amenable number.

20907449 is a deficient number, since it is larger than the sum of its proper divisors (1).

20907449 is an equidigital number, since it uses as much as digits as its factorization.

20907449 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 18144, while the sum is 35.

The square root of 20907449 is about 4572.4664022823. The cubic root of 20907449 is about 275.4865172809.

The spelling of 20907449 in words is "twenty million, nine hundred seven thousand, four hundred forty-nine".