20891093 has 2 divisors, whose sum is σ = 20891094. Its totient is φ = 20891092.

The previous prime is 20891083. The next prime is 20891131. The reversal of 20891093 is 39019802.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19298449 + 1592644 = 4393^2 + 1262^2 .

It is a cyclic number.

It is not a de Polignac number, because 20891093 - 2⁶ = 20891029 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20891033) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10445546 + 10445547.

It is an arithmetic number, because the mean of its divisors is an integer number (10445547).

Almost surely, 2^20891093 is an apocalyptic number.

It is an amenable number.

20891093 is a deficient number, since it is larger than the sum of its proper divisors (1).

20891093 is an equidigital number, since it uses as much as digits as its factorization.

20891093 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3888, while the sum is 32.

The square root of 20891093 is about 4570.6775208934. The cubic root of 20891093 is about 275.4146603880.

The spelling of 20891093 in words is "twenty million, eight hundred ninety-one thousand, ninety-three".