20017157 has 4 divisors (see below), whose sum is σ = 20063820. Its totient is φ = 19970496.

The previous prime is 20017147. The next prime is 20017169. The reversal of 20017157 is 75171002.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 13184161 + 6832996 = 3631^2 + 2614^2 .

It is a cyclic number.

It is not a de Polignac number, because 20017157 - 2⁴ = 20017141 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20017117) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 22682 + ... + 23547.

It is an arithmetic number, because the mean of its divisors is an integer number (5015955).

Almost surely, 2^20017157 is an apocalyptic number.

It is an amenable number.

20017157 is a deficient number, since it is larger than the sum of its proper divisors (46663).

20017157 is an equidigital number, since it uses as much as digits as its factorization.

20017157 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 46662.

The product of its (nonzero) digits is 490, while the sum is 23.

The square root of 20017157 is about 4474.0537547061. The cubic root of 20017157 is about 271.5193582467.

Adding to 20017157 its reverse (75171002), we get a palindrome (95188159).

The spelling of 20017157 in words is "twenty million, seventeen thousand, one hundred fifty-seven".