20867645 has 8 divisors (see below), whose sum is σ = 25233120. Its totient is φ = 16566160.

The previous prime is 20867603. The next prime is 20867663. The reversal of 20867645 is 54676802.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 20867645 - 2¹⁰ = 20866621 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 20867599 and 20867608.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 15275 + ... + 16584.

It is an arithmetic number, because the mean of its divisors is an integer number (3154140).

Almost surely, 2^20867645 is an apocalyptic number.

It is an amenable number.

20867645 is a deficient number, since it is larger than the sum of its proper divisors (4365475).

20867645 is a wasteful number, since it uses less digits than its factorization.

20867645 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 31995.

The product of its (nonzero) digits is 80640, while the sum is 38.

The square root of 20867645 is about 4568.1117543248. Note that the first 3 decimals coincide. The cubic root of 20867645 is about 275.3115807235.

It can be divided in two parts, 20867 and 645, that added together give a palindrome (21512).

The spelling of 20867645 in words is "twenty million, eight hundred sixty-seven thousand, six hundred forty-five".