20931266 has 8 divisors (see below), whose sum is σ = 31428540. Its totient is φ = 10455088.

The previous prime is 20931263. The next prime is 20931289. The reversal of 20931266 is 66213902.

It can be written as a sum of positive squares in 2 ways, for example, as 19175641 + 1755625 = 4379^2 + 1325^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not an unprimeable number, because it can be changed into a prime (20931263) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2501 + ... + 6936.

Almost surely, 2^20931266 is an apocalyptic number.

20931266 is a deficient number, since it is larger than the sum of its proper divisors (10497274).

20931266 is a wasteful number, since it uses less digits than its factorization.

20931266 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10548.

The product of its (nonzero) digits is 3888, while the sum is 29.

The square root of 20931266 is about 4575.0700541085. The cubic root of 20931266 is about 275.5910856337.

The spelling of 20931266 in words is "twenty million, nine hundred thirty-one thousand, two hundred sixty-six".