20842157 has 8 divisors (see below), whose sum is σ = 24146496. Its totient is φ = 17619552.

The previous prime is 20842147. The next prime is 20842169. The reversal of 20842157 is 75124802.

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

It is a cyclic number.

It is not a de Polignac number, because 20842157 - 2⁴ = 20842141 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 (20842127) 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 in 7 ways as a sum of consecutive naturals, for example, 19883 + ... + 20904.

It is an arithmetic number, because the mean of its divisors is an integer number (3018312).

Almost surely, 2^20842157 is an apocalyptic number.

It is an amenable number.

20842157 is a deficient number, since it is larger than the sum of its proper divisors (3304339).

20842157 is an equidigital number, since it uses as much as digits as its factorization.

20842157 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40867.

The product of its (nonzero) digits is 4480, while the sum is 29.

The square root of 20842157 is about 4565.3211278069. The cubic root of 20842157 is about 275.1994453987.

Adding to 20842157 its reverse (75124802), we get a palindrome (95966959).

The spelling of 20842157 in words is "twenty million, eight hundred forty-two thousand, one hundred fifty-seven".