20643546 has 32 divisors (see below), whose sum is σ = 51475968. Its totient is φ = 5361840.

The previous prime is 20643529. The next prime is 20643547. The reversal of 20643546 is 64534602.

It is not an unprimeable number, because it can be changed into a prime (20643547) 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 15 ways as a sum of consecutive naturals, for example, 21880 + ... + 22803.

It is an arithmetic number, because the mean of its divisors is an integer number (1608624).

Almost surely, 2^20643546 is an apocalyptic number.

20643546 is an abundant number, since it is smaller than the sum of its proper divisors (30832422).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20643546 is a wasteful number, since it uses less digits than its factorization.

20643546 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 44706.

The product of its (nonzero) digits is 17280, while the sum is 30.

The square root of 20643546 is about 4543.5169197440. The cubic root of 20643546 is about 274.3225019637.

The spelling of 20643546 in words is "twenty million, six hundred forty-three thousand, five hundred forty-six".