20491049 has 2 divisors, whose sum is σ = 20491050. Its totient is φ = 20491048.

The previous prime is 20491043. The next prime is 20491057. The reversal of 20491049 is 94019402.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16362025 + 4129024 = 4045^2 + 2032^2 .

It is a cyclic number.

It is not a de Polignac number, because 20491049 - 2¹² = 20486953 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (20491043) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10245524 + 10245525.

It is an arithmetic number, because the mean of its divisors is an integer number (10245525).

Almost surely, 2^20491049 is an apocalyptic number.

It is an amenable number.

20491049 is a deficient number, since it is larger than the sum of its proper divisors (1).

20491049 is an equidigital number, since it uses as much as digits as its factorization.

20491049 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2592, while the sum is 29.

The square root of 20491049 is about 4526.7039885550. The cubic root of 20491049 is about 273.6453445088.

The spelling of 20491049 in words is "twenty million, four hundred ninety-one thousand, forty-nine".