20853439 has 2 divisors, whose sum is σ = 20853440. Its totient is φ = 20853438.

The previous prime is 20853419. The next prime is 20853473. The reversal of 20853439 is 93435802.

It is a happy number.

It is an a-pointer prime, because the next prime (20853473) can be obtained adding 20853439 to its sum of digits (34).

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20853439 - 2¹⁷ = 20722367 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20853419) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10426719 + 10426720.

It is an arithmetic number, because the mean of its divisors is an integer number (10426720).

Almost surely, 2^20853439 is an apocalyptic number.

20853439 is a deficient number, since it is larger than the sum of its proper divisors (1).

20853439 is an equidigital number, since it uses as much as digits as its factorization.

20853439 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 25920, while the sum is 34.

The square root of 20853439 is about 4566.5565801816. The cubic root of 20853439 is about 275.2490922130.

The spelling of 20853439 in words is "twenty million, eight hundred fifty-three thousand, four hundred thirty-nine".