20991126 has 16 divisors (see below), whose sum is σ = 45211824. Its totient is φ = 6458784.

The previous prime is 20991121. The next prime is 20991149. The reversal of 20991126 is 62119902.

It is a happy number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 20991093 and 20991102.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20991121) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 134481 + ... + 134636.

It is an arithmetic number, because the mean of its divisors is an integer number (2825739).

Almost surely, 2^20991126 is an apocalyptic number.

20991126 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

20991126 is an abundant number, since it is smaller than the sum of its proper divisors (24220698).

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

20991126 is a wasteful number, since it uses less digits than its factorization.

20991126 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 269135.

The product of its (nonzero) digits is 1944, while the sum is 30.

The square root of 20991126 is about 4581.6073598684. The cubic root of 20991126 is about 275.8535507452.

The spelling of 20991126 in words is "twenty million, nine hundred ninety-one thousand, one hundred twenty-six".