20745808 has 10 divisors (see below), whose sum is σ = 40195034. Its totient is φ = 10372896.

The previous prime is 20745799. The next prime is 20745833. The reversal of 20745808 is 80854702.

It can be written as a sum of positive squares in only one way, i.e., 20684304 + 61504 = 4548^2 + 248^2 .

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 648291 + ... + 648322.

Almost surely, 2^20745808 is an apocalyptic number.

It is an amenable number.

20745808 is a deficient number, since it is larger than the sum of its proper divisors (19449226).

20745808 is a wasteful number, since it uses less digits than its factorization.

20745808 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1296621 (or 1296615 counting only the distinct ones).

The product of its (nonzero) digits is 17920, while the sum is 34.

The square root of 20745808 is about 4554.7566345525. The cubic root of 20745808 is about 274.7747268069.

The spelling of 20745808 in words is "twenty million, seven hundred forty-five thousand, eight hundred eight".