20853645 has 32 divisors (see below), whose sum is σ = 36018432. Its totient is φ = 10263552.

The previous prime is 20853641. The next prime is 20853649. The reversal of 20853645 is 54635802.

It is an interprime number because it is at equal distance from previous prime (20853641) and next prime (20853649).

It is not a de Polignac number, because 20853645 - 2² = 20853641 is a prime.

It is a super-3 number, since 3×20853645³ (a number of 23 digits) contains 333 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20853641) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 12744 + ... + 14286.

It is an arithmetic number, because the mean of its divisors is an integer number (1125576).

Almost surely, 2^20853645 is an apocalyptic number.

It is an amenable number.

20853645 is a deficient number, since it is larger than the sum of its proper divisors (15164787).

20853645 is a wasteful number, since it uses less digits than its factorization.

20853645 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1621.

The product of its (nonzero) digits is 28800, while the sum is 33.

The square root of 20853645 is about 4566.5791354142. The cubic root of 20853645 is about 275.2499985563.

The spelling of 20853645 in words is "twenty million, eight hundred fifty-three thousand, six hundred forty-five".