20638743 has 4 divisors (see below), whose sum is σ = 27518328. Its totient is φ = 13759160.

The previous prime is 20638741. The next prime is 20638757. The reversal of 20638743 is 34783602.

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

It is a cyclic number.

It is not a de Polignac number, because 20638743 - 2¹ = 20638741 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20638741) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3439788 + ... + 3439793.

It is an arithmetic number, because the mean of its divisors is an integer number (6879582).

Almost surely, 2^20638743 is an apocalyptic number.

20638743 is a deficient number, since it is larger than the sum of its proper divisors (6879585).

20638743 is an equidigital number, since it uses as much as digits as its factorization.

20638743 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6879584.

The product of its (nonzero) digits is 24192, while the sum is 33.

The square root of 20638743 is about 4542.9883336852. The cubic root of 20638743 is about 274.3012253675.

The spelling of 20638743 in words is "twenty million, six hundred thirty-eight thousand, seven hundred forty-three".