20643734 has 8 divisors (see below), whose sum is σ = 31285128. Its totient is φ = 10215360.

The previous prime is 20643731. The next prime is 20643739. The reversal of 20643734 is 43734602.

It is a happy number.

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

It is a junction number, because it is equal to n+sod(n) for n = 20643697 and 20643706.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20643731) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 53012 + ... + 53399.

It is an arithmetic number, because the mean of its divisors is an integer number (3910641).

Almost surely, 2^20643734 is an apocalyptic number.

20643734 is a deficient number, since it is larger than the sum of its proper divisors (10641394).

20643734 is a wasteful number, since it uses less digits than its factorization.

20643734 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 106510.

The product of its (nonzero) digits is 12096, while the sum is 29.

The square root of 20643734 is about 4543.5376085161. The cubic root of 20643734 is about 274.3233347094.

The spelling of 20643734 in words is "twenty million, six hundred forty-three thousand, seven hundred thirty-four".