20009747 has 4 divisors (see below), whose sum is σ = 20879760. Its totient is φ = 19139736.

The previous prime is 20009741. The next prime is 20009753. The reversal of 20009747 is 74790002.

It is a semiprime because it is the product of two primes.

It is an interprime number because it is at equal distance from previous prime (20009741) and next prime (20009753).

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20009747 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20009741) 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 3 ways as a sum of consecutive naturals, for example, 434972 + ... + 435017.

It is an arithmetic number, because the mean of its divisors is an integer number (5219940).

Almost surely, 2^20009747 is an apocalyptic number.

20009747 is a deficient number, since it is larger than the sum of its proper divisors (870013).

20009747 is an equidigital number, since it uses as much as digits as its factorization.

20009747 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 870012.

The product of its (nonzero) digits is 3528, while the sum is 29.

The square root of 20009747 is about 4473.2255699886. The cubic root of 20009747 is about 271.4858502123.

Adding to 20009747 its reverse (74790002), we get a palindrome (94799749).

The spelling of 20009747 in words is "twenty million, nine thousand, seven hundred forty-seven".