20744647 has 16 divisors (see below), whose sum is σ = 26498304. Its totient is φ = 15768000.

The previous prime is 20744639. The next prime is 20744663. The reversal of 20744647 is 74644702.

It is a cyclic number.

It is not a de Polignac number, because 20744647 - 2³ = 20744639 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20744617) 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 15 ways as a sum of consecutive naturals, for example, 129 + ... + 6442.

It is an arithmetic number, because the mean of its divisors is an integer number (1656144).

Almost surely, 2^20744647 is an apocalyptic number.

20744647 is a deficient number, since it is larger than the sum of its proper divisors (5753657).

20744647 is a wasteful number, since it uses less digits than its factorization.

20744647 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6630.

The product of its (nonzero) digits is 37632, while the sum is 34.

The square root of 20744647 is about 4554.6291835889. The cubic root of 20744647 is about 274.7696009616.

The spelling of 20744647 in words is "twenty million, seven hundred forty-four thousand, six hundred forty-seven".