20851253 has 2 divisors, whose sum is σ = 20851254. Its totient is φ = 20851252.

The previous prime is 20851223. The next prime is 20851267. The reversal of 20851253 is 35215802.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 14002564 + 6848689 = 3742^2 + 2617^2 .

It is a cyclic number.

It is not a de Polignac number, because 20851253 - 2¹⁸ = 20589109 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 (20851213) 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, 10425626 + 10425627.

It is an arithmetic number, because the mean of its divisors is an integer number (10425627).

Almost surely, 2^20851253 is an apocalyptic number.

It is an amenable number.

20851253 is a deficient number, since it is larger than the sum of its proper divisors (1).

20851253 is an equidigital number, since it uses as much as digits as its factorization.

20851253 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2400, while the sum is 26.

The square root of 20851253 is about 4566.3172250732. The cubic root of 20851253 is about 275.2394740466.

The spelling of 20851253 in words is "twenty million, eight hundred fifty-one thousand, two hundred fifty-three".