20853397 has 4 divisors (see below), whose sum is σ = 20869420. Its totient is φ = 20837376.

The previous prime is 20853389. The next prime is 20853401. The reversal of 20853397 is 79335802.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 1572516 + 19280881 = 1254^2 + 4391^2 .

It is a cyclic number.

It is not a de Polignac number, because 20853397 - 2³ = 20853389 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20853377) 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 in 3 ways as a sum of consecutive naturals, for example, 5868 + ... + 8725.

It is an arithmetic number, because the mean of its divisors is an integer number (5217355).

Almost surely, 2^20853397 is an apocalyptic number.

20853397 is the 2637-th hex number.

It is an amenable number.

20853397 is a deficient number, since it is larger than the sum of its proper divisors (16023).

20853397 is a wasteful number, since it uses less digits than its factorization.

20853397 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16022.

The product of its (nonzero) digits is 45360, while the sum is 37.

The square root of 20853397 is about 4566.5519815283. The cubic root of 20853397 is about 275.2489074238.

The spelling of 20853397 in words is "twenty million, eight hundred fifty-three thousand, three hundred ninety-seven".