20891133 has 12 divisors (see below), whose sum is σ = 30688320. Its totient is φ = 13691016.

The previous prime is 20891131. The next prime is 20891149. The reversal of 20891133 is 33119802.

It is not a de Polignac number, because 20891133 - 2¹ = 20891131 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 20891097 and 20891106.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20891131) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 19141 + ... + 20202.

It is an arithmetic number, because the mean of its divisors is an integer number (2557360).

Almost surely, 2^20891133 is an apocalyptic number.

It is an amenable number.

20891133 is a deficient number, since it is larger than the sum of its proper divisors (9797187).

20891133 is a wasteful number, since it uses less digits than its factorization.

20891133 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 39408 (or 39405 counting only the distinct ones).

The product of its (nonzero) digits is 1296, while the sum is 27.

The square root of 20891133 is about 4570.6818966102. The cubic root of 20891133 is about 275.4148361659.

The spelling of 20891133 in words is "twenty million, eight hundred ninety-one thousand, one hundred thirty-three".