20645606 has 4 divisors (see below), whose sum is σ = 30968412. Its totient is φ = 10322802.

The previous prime is 20645579. The next prime is 20645671. The reversal of 20645606 is 60654602.

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

It is a congruent number.

It is an unprimeable number.

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 as a sum of consecutive naturals, namely, 5161400 + ... + 5161403.

It is an arithmetic number, because the mean of its divisors is an integer number (7742103).

Almost surely, 2^20645606 is an apocalyptic number.

20645606 is a deficient number, since it is larger than the sum of its proper divisors (10322806).

20645606 is a wasteful number, since it uses less digits than its factorization.

20645606 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10322805.

The product of its (nonzero) digits is 8640, while the sum is 29.

The square root of 20645606 is about 4543.7436107245. The cubic root of 20645606 is about 274.3316264548.

The spelling of 20645606 in words is "twenty million, six hundred forty-five thousand, six hundred six".