20613645 has 48 divisors (see below), whose sum is σ = 38892672. Its totient is φ = 10039680.

The previous prime is 20613601. The next prime is 20613647. The reversal of 20613645 is 54631602.

20613645 is a `hidden beast` number, since 2 + 0 + 6 + 13 + 645 = 666.

It is not a de Polignac number, because 20613645 - 2¹⁰ = 20612621 is a prime.

It is a super-3 number, since 3×20613645³ (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 (20613647) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 97590 + ... + 97800.

It is an arithmetic number, because the mean of its divisors is an integer number (810264).

Almost surely, 2^20613645 is an apocalyptic number.

It is an amenable number.

20613645 is a deficient number, since it is larger than the sum of its proper divisors (18279027).

20613645 is a wasteful number, since it uses less digits than its factorization.

20613645 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 402 (or 399 counting only the distinct ones).

The product of its (nonzero) digits is 4320, while the sum is 27.

The square root of 20613645 is about 4540.2252146782. The cubic root of 20613645 is about 274.1899911277.

The spelling of 20613645 in words is "twenty million, six hundred thirteen thousand, six hundred forty-five".