20147549 has 2 divisors, whose sum is σ = 20147550. Its totient is φ = 20147548.

The previous prime is 20147539. The next prime is 20147587. The reversal of 20147549 is 94574102.

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., 16605625 + 3541924 = 4075^2 + 1882^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20147549 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 (20147509) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10073774 + 10073775.

It is an arithmetic number, because the mean of its divisors is an integer number (10073775).

Almost surely, 2^20147549 is an apocalyptic number.

It is an amenable number.

20147549 is a deficient number, since it is larger than the sum of its proper divisors (1).

20147549 is an equidigital number, since it uses as much as digits as its factorization.

20147549 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 10080, while the sum is 32.

The square root of 20147549 is about 4488.6021209281. The cubic root of 20147549 is about 272.1076428407.

The spelling of 20147549 in words is "twenty million, one hundred forty-seven thousand, five hundred forty-nine".