20124649 has 2 divisors, whose sum is σ = 20124650. Its totient is φ = 20124648.

The previous prime is 20124647. The next prime is 20124653. The reversal of 20124649 is 94642102.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19740249 + 384400 = 4443^2 + 620^2 .

It is a cyclic number.

It is not a de Polignac number, because 20124649 - 2¹ = 20124647 is a prime.

Together with 20124647, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (20124647) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10062324 + 10062325.

It is an arithmetic number, because the mean of its divisors is an integer number (10062325).

Almost surely, 2^20124649 is an apocalyptic number.

It is an amenable number.

20124649 is a deficient number, since it is larger than the sum of its proper divisors (1).

20124649 is an equidigital number, since it uses as much as digits as its factorization.

20124649 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3456, while the sum is 28.

The square root of 20124649 is about 4486.0504901305. The cubic root of 20124649 is about 272.0045099094.

It can be divided in two parts, 201246 and 49, that added together give a triangular number (201295 = T₆₃₄).

The spelling of 20124649 in words is "twenty million, one hundred twenty-four thousand, six hundred forty-nine".