20557051 has 2 divisors, whose sum is σ = 20557052. Its totient is φ = 20557050.

The previous prime is 20557039. The next prime is 20557067. The reversal of 20557051 is 15075502.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20557051 - 2⁷ = 20556923 is a prime.

It is equal to p_1303639 and since 20557051 and 1303639 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (20557091) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10278525 + 10278526.

It is an arithmetic number, because the mean of its divisors is an integer number (10278526).

Almost surely, 2^20557051 is an apocalyptic number.

20557051 is a deficient number, since it is larger than the sum of its proper divisors (1).

20557051 is an equidigital number, since it uses as much as digits as its factorization.

20557051 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1750, while the sum is 25.

The square root of 20557051 is about 4533.9884208057. The cubic root of 20557051 is about 273.9388349805.

The spelling of 20557051 in words is "twenty million, five hundred fifty-seven thousand, fifty-one".