20744645 has 8 divisors (see below), whose sum is σ = 24942840. Its totient is φ = 16562880.

The previous prime is 20744639. The next prime is 20744663. The reversal of 20744645 is 54644702.

It can be written as a sum of positive squares in 4 ways, for example, as 5635876 + 15108769 = 2374^2 + 3887^2 .

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

It is not a de Polignac number, because 20744645 - 2⁸ = 20744389 is a prime.

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, 1130 + ... + 6539.

It is an arithmetic number, because the mean of its divisors is an integer number (3117855).

Almost surely, 2^20744645 is an apocalyptic number.

It is an amenable number.

20744645 is a deficient number, since it is larger than the sum of its proper divisors (4198195).

20744645 is an equidigital number, since it uses as much as digits as its factorization.

20744645 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8215.

The product of its (nonzero) digits is 26880, while the sum is 32.

The square root of 20744645 is about 4554.6289640321. The cubic root of 20744645 is about 274.7695921314.

The spelling of 20744645 in words is "twenty million, seven hundred forty-four thousand, six hundred forty-five".