20208157 has 4 divisors (see below), whose sum is σ = 20905020. Its totient is φ = 19511296.

The previous prime is 20208109. The next prime is 20208163. The reversal of 20208157 is 75180202.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 75180202 = 2 ⋅37590101.

It can be written as a sum of positive squares in 2 ways, for example, as 8415801 + 11792356 = 2901^2 + 3434^2 .

It is a cyclic number.

It is not a de Polignac number, because 20208157 - 2⁷ = 20208029 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 (20200157) 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, 348388 + ... + 348445.

It is an arithmetic number, because the mean of its divisors is an integer number (5226255).

Almost surely, 2^20208157 is an apocalyptic number.

It is an amenable number.

20208157 is a deficient number, since it is larger than the sum of its proper divisors (696863).

20208157 is an equidigital number, since it uses as much as digits as its factorization.

20208157 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 696862.

The product of its (nonzero) digits is 1120, while the sum is 25.

The square root of 20208157 is about 4495.3483735969. The cubic root of 20208157 is about 272.3802217465.

Adding to 20208157 its reverse (75180202), we get a palindrome (95388359).

The spelling of 20208157 in words is "twenty million, two hundred eight thousand, one hundred fifty-seven".