20909766 has 32 divisors (see below), whose sum is σ = 44352000. Its totient is φ = 6553440.

The previous prime is 20909753. The next prime is 20909767. The reversal of 20909766 is 66790902.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20909767) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 16371 + ... + 17601.

It is an arithmetic number, because the mean of its divisors is an integer number (1386000).

Almost surely, 2^20909766 is an apocalyptic number.

20909766 is an abundant number, since it is smaller than the sum of its proper divisors (23442234).

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

20909766 is a wasteful number, since it uses less digits than its factorization.

20909766 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1404.

The product of its (nonzero) digits is 40824, while the sum is 39.

The square root of 20909766 is about 4572.7197596179. The cubic root of 20909766 is about 275.4966935373.

The spelling of 20909766 in words is "twenty million, nine hundred nine thousand, seven hundred sixty-six".