20439149 has 2 divisors, whose sum is σ = 20439150. Its totient is φ = 20439148.

The previous prime is 20439143. The next prime is 20439169. The reversal of 20439149 is 94193402.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 11854249 + 8584900 = 3443^2 + 2930^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20439149 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20439143) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10219574 + 10219575.

It is an arithmetic number, because the mean of its divisors is an integer number (10219575).

Almost surely, 2^20439149 is an apocalyptic number.

It is an amenable number.

20439149 is a deficient number, since it is larger than the sum of its proper divisors (1).

20439149 is an equidigital number, since it uses as much as digits as its factorization.

20439149 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 7776, while the sum is 32.

The square root of 20439149 is about 4520.9677061443. The cubic root of 20439149 is about 273.4141183316.

The spelling of 20439149 in words is "twenty million, four hundred thirty-nine thousand, one hundred forty-nine".