20909406 has 32 divisors (see below), whose sum is σ = 49443840. Its totient is φ = 5767776.

The previous prime is 20909389. The next prime is 20909419. The reversal of 20909406 is 60490902.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7366 + ... + 9801.

It is an arithmetic number, because the mean of its divisors is an integer number (1545120).

Almost surely, 2^20909406 is an apocalyptic number.

20909406 is an abundant number, since it is smaller than the sum of its proper divisors (28534434).

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

20909406 is a wasteful number, since it uses less digits than its factorization.

20909406 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17208.

The product of its (nonzero) digits is 3888, while the sum is 30.

The square root of 20909406 is about 4572.6803955667. The cubic root of 20909406 is about 275.4951124678.

The spelling of 20909406 in words is "twenty million, nine hundred nine thousand, four hundred six".