20404739 has 2 divisors, whose sum is σ = 20404740. Its totient is φ = 20404738.

The previous prime is 20404729. The next prime is 20404753. The reversal of 20404739 is 93740402.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20404739 is a prime.

It is not a weakly prime, because it can be changed into another prime (20404729) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10202369 + 10202370.

It is an arithmetic number, because the mean of its divisors is an integer number (10202370).

Almost surely, 2^20404739 is an apocalyptic number.

20404739 is a deficient number, since it is larger than the sum of its proper divisors (1).

20404739 is an equidigital number, since it uses as much as digits as its factorization.

20404739 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 6048, while the sum is 29.

The square root of 20404739 is about 4517.1605019083. The cubic root of 20404739 is about 273.2605981692.

The spelling of 20404739 in words is "twenty million, four hundred four thousand, seven hundred thirty-nine".