20890057 has 2 divisors, whose sum is σ = 20890058. Its totient is φ = 20890056.

The previous prime is 20890031. The next prime is 20890061. The reversal of 20890057 is 75009802.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18567481 + 2322576 = 4309^2 + 1524^2 .

It is a cyclic number.

It is not a de Polignac number, because 20890057 - 2⁷ = 20889929 is a prime.

It is not a weakly prime, because it can be changed into another prime (20890027) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10445028 + 10445029.

It is an arithmetic number, because the mean of its divisors is an integer number (10445029).

Almost surely, 2^20890057 is an apocalyptic number.

It is an amenable number.

20890057 is a deficient number, since it is larger than the sum of its proper divisors (1).

20890057 is an equidigital number, since it uses as much as digits as its factorization.

20890057 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5040, while the sum is 31.

The square root of 20890057 is about 4570.5641883689. The cubic root of 20890057 is about 275.4101076614.

Adding to 20890057 its reverse (75009802), we get a palindrome (95899859).

The spelling of 20890057 in words is "twenty million, eight hundred ninety thousand, fifty-seven".