20891033 has 2 divisors, whose sum is σ = 20891034. Its totient is φ = 20891032.

The previous prime is 20891029. The next prime is 20891041. The reversal of 20891033 is 33019802.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 15264649 + 5626384 = 3907^2 + 2372^2 .

It is a cyclic number.

It is not a de Polignac number, because 20891033 - 2² = 20891029 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 20890993 and 20891011.

It is not a weakly prime, because it can be changed into another prime (20891083) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10445516 + 10445517.

It is an arithmetic number, because the mean of its divisors is an integer number (10445517).

Almost surely, 2^20891033 is an apocalyptic number.

It is an amenable number.

20891033 is a deficient number, since it is larger than the sum of its proper divisors (1).

20891033 is an equidigital number, since it uses as much as digits as its factorization.

20891033 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1296, while the sum is 26.

The square root of 20891033 is about 4570.6709573103. The cubic root of 20891033 is about 275.4143967207.

The spelling of 20891033 in words is "twenty million, eight hundred ninety-one thousand, thirty-three".