20618157 has 8 divisors (see below), whose sum is σ = 31418176. Its totient is φ = 11781792.

The previous prime is 20618141. The next prime is 20618197. The reversal of 20618157 is 75181602.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 20618157 - 2⁴ = 20618141 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 (20618107) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 490888 + ... + 490929.

It is an arithmetic number, because the mean of its divisors is an integer number (3927272).

Almost surely, 2^20618157 is an apocalyptic number.

It is an amenable number.

20618157 is a deficient number, since it is larger than the sum of its proper divisors (10800019).

20618157 is an equidigital number, since it uses as much as digits as its factorization.

20618157 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 981827.

The product of its (nonzero) digits is 3360, while the sum is 30.

The square root of 20618157 is about 4540.7220791412. The cubic root of 20618157 is about 274.2099949486.

Adding to 20618157 its reverse (75181602), we get a palindrome (95799759).

The spelling of 20618157 in words is "twenty million, six hundred eighteen thousand, one hundred fifty-seven".