20845357 has 4 divisors (see below), whose sum is σ = 22448860. Its totient is φ = 19241856.

The previous prime is 20845339. The next prime is 20845373. The reversal of 20845357 is 75354802.

It is a happy number.

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 1713481 + 19131876 = 1309^2 + 4374^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20845357 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 (20845327) 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, 801732 + ... + 801757.

It is an arithmetic number, because the mean of its divisors is an integer number (5612215).

Almost surely, 2^20845357 is an apocalyptic number.

It is an amenable number.

20845357 is a deficient number, since it is larger than the sum of its proper divisors (1603503).

20845357 is a wasteful number, since it uses less digits than its factorization.

20845357 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1603502.

The product of its (nonzero) digits is 33600, while the sum is 34.

The square root of 20845357 is about 4565.6715825823. The cubic root of 20845357 is about 275.2135289244.

The spelling of 20845357 in words is "twenty million, eight hundred forty-five thousand, three hundred fifty-seven".