20740649 has 8 divisors (see below), whose sum is σ = 21374280. Its totient is φ = 20116096.

The previous prime is 20740633. The next prime is 20740673. The reversal of 20740649 is 94604702.

It can be written as a sum of positive squares in 4 ways, for example, as 2190400 + 18550249 = 1480^2 + 4307^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 20740649 - 2⁴ = 20740633 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20740679) 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 7 ways as a sum of consecutive naturals, for example, 2519 + ... + 6915.

It is an arithmetic number, because the mean of its divisors is an integer number (2671785).

Almost surely, 2^20740649 is an apocalyptic number.

It is an amenable number.

20740649 is a deficient number, since it is larger than the sum of its proper divisors (633631).

20740649 is an equidigital number, since it uses as much as digits as its factorization.

20740649 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4539.

The product of its (nonzero) digits is 12096, while the sum is 32.

The square root of 20740649 is about 4554.1902683133. The cubic root of 20740649 is about 274.7519482238.

The spelling of 20740649 in words is "twenty million, seven hundred forty thousand, six hundred forty-nine".