20809772 has 12 divisors (see below), whose sum is σ = 37034760. Its totient is φ = 10228416.

The previous prime is 20809759. The next prime is 20809777. The reversal of 20809772 is 27790802.

It is a super-2 number, since 2×20809772² = 866093221383968, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (20809777) by changing a digit.

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 in 3 ways as a sum of consecutive naturals, for example, 43853 + ... + 44324.

It is an arithmetic number, because the mean of its divisors is an integer number (3086230).

Almost surely, 2^20809772 is an apocalyptic number.

It is an amenable number.

20809772 is a deficient number, since it is larger than the sum of its proper divisors (16224988).

20809772 is a wasteful number, since it uses less digits than its factorization.

20809772 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 88240 (or 88238 counting only the distinct ones).

The product of its (nonzero) digits is 14112, while the sum is 35.

The square root of 20809772 is about 4561.7729009673. The cubic root of 20809772 is about 275.0568345341.

The spelling of 20809772 in words is "twenty million, eight hundred nine thousand, seven hundred seventy-two".