20853649 has 2 divisors, whose sum is σ = 20853650. Its totient is φ = 20853648.

The previous prime is 20853641. The next prime is 20853661. The reversal of 20853649 is 94635802.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18190225 + 2663424 = 4265^2 + 1632^2 .

It is a cyclic number.

It is not a de Polignac number, because 20853649 - 2³ = 20853641 is a prime.

It is not a weakly prime, because it can be changed into another prime (20853641) 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, 10426824 + 10426825.

It is an arithmetic number, because the mean of its divisors is an integer number (10426825).

Almost surely, 2^20853649 is an apocalyptic number.

It is an amenable number.

20853649 is a deficient number, since it is larger than the sum of its proper divisors (1).

20853649 is an equidigital number, since it uses as much as digits as its factorization.

20853649 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 51840, while the sum is 37.

The square root of 20853649 is about 4566.5795733787. The cubic root of 20853649 is about 275.2500161552.

The spelling of 20853649 in words is "twenty million, eight hundred fifty-three thousand, six hundred forty-nine".