20634605 has 4 divisors (see below), whose sum is σ = 24761532. Its totient is φ = 16507680.

The previous prime is 20634571. The next prime is 20634613. The reversal of 20634605 is 50643602.

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

It can be written as a sum of positive squares in 2 ways, for example, as 7946761 + 12687844 = 2819^2 + 3562^2 .

It is not a de Polignac number, because 20634605 - 2⁶ = 20634541 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

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, 2063456 + ... + 2063465.

It is an arithmetic number, because the mean of its divisors is an integer number (6190383).

Almost surely, 2^20634605 is an apocalyptic number.

It is an amenable number.

20634605 is a deficient number, since it is larger than the sum of its proper divisors (4126927).

20634605 is an equidigital number, since it uses as much as digits as its factorization.

20634605 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4126926.

The product of its (nonzero) digits is 4320, while the sum is 26.

The square root of 20634605 is about 4542.5328837555. The cubic root of 20634605 is about 274.2828919781.

The spelling of 20634605 in words is "twenty million, six hundred thirty-four thousand, six hundred five".