20328857 has 2 divisors, whose sum is σ = 20328858. Its totient is φ = 20328856.

The previous prime is 20328853. The next prime is 20328859. The reversal of 20328857 is 75882302.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 11262736 + 9066121 = 3356^2 + 3011^2 .

It is a cyclic number.

It is not a de Polignac number, because 20328857 - 2² = 20328853 is a prime.

Together with 20328859, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (20328853) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10164428 + 10164429.

It is an arithmetic number, because the mean of its divisors is an integer number (10164429).

Almost surely, 2^20328857 is an apocalyptic number.

It is an amenable number.

20328857 is a deficient number, since it is larger than the sum of its proper divisors (1).

20328857 is an equidigital number, since it uses as much as digits as its factorization.

20328857 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 26880, while the sum is 35.

The square root of 20328857 is about 4508.7533753799. The cubic root of 20328857 is about 272.9214397342.

The spelling of 20328857 in words is "twenty million, three hundred twenty-eight thousand, eight hundred fifty-seven".