20404949 has 2 divisors, whose sum is σ = 20404950. Its totient is φ = 20404948.

The previous prime is 20404939. The next prime is 20404957. The reversal of 20404949 is 94940402.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 10608049 + 9796900 = 3257^2 + 3130^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20404949 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20404939) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10202474 + 10202475.

It is an arithmetic number, because the mean of its divisors is an integer number (10202475).

Almost surely, 2^20404949 is an apocalyptic number.

It is an amenable number.

20404949 is a deficient number, since it is larger than the sum of its proper divisors (1).

20404949 is an equidigital number, since it uses as much as digits as its factorization.

20404949 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 10368, while the sum is 32.

The square root of 20404949 is about 4517.1837465394. The cubic root of 20404949 is about 273.2615356071.

The spelling of 20404949 in words is "twenty million, four hundred four thousand, nine hundred forty-nine".