20538157 has 2 divisors, whose sum is σ = 20538158. Its totient is φ = 20538156.

The previous prime is 20538143. The next prime is 20538173. The reversal of 20538157 is 75183502.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 14243076 + 6295081 = 3774^2 + 2509^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20538157 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20538127) 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, 10269078 + 10269079.

It is an arithmetic number, because the mean of its divisors is an integer number (10269079).

Almost surely, 2^20538157 is an apocalyptic number.

It is an amenable number.

20538157 is a deficient number, since it is larger than the sum of its proper divisors (1).

20538157 is an equidigital number, since it uses as much as digits as its factorization.

20538157 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 8400, while the sum is 31.

The square root of 20538157 is about 4531.9043458573. The cubic root of 20538157 is about 273.8548834635.

The spelling of 20538157 in words is "twenty million, five hundred thirty-eight thousand, one hundred fifty-seven".