20891473 has 2 divisors, whose sum is σ = 20891474. Its totient is φ = 20891472.

The previous prime is 20891461. The next prime is 20891503. The reversal of 20891473 is 37419802.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18045504 + 2845969 = 4248^2 + 1687^2 .

It is a cyclic number.

It is not a de Polignac number, because 20891473 - 2¹⁷ = 20760401 is a prime.

It is not a weakly prime, because it can be changed into another prime (20891413) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10445736 + 10445737.

It is an arithmetic number, because the mean of its divisors is an integer number (10445737).

Almost surely, 2^20891473 is an apocalyptic number.

It is an amenable number.

20891473 is a deficient number, since it is larger than the sum of its proper divisors (1).

20891473 is an equidigital number, since it uses as much as digits as its factorization.

20891473 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 12096, while the sum is 34.

The square root of 20891473 is about 4570.7190900339. The cubic root of 20891473 is about 275.4163302693.

The spelling of 20891473 in words is "twenty million, eight hundred ninety-one thousand, four hundred seventy-three".