20420157 has 8 divisors (see below), whose sum is σ = 27571840. Its totient is φ = 13440960.

The previous prime is 20420129. The next prime is 20420167. The reversal of 20420157 is 75102402.

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

It is not a de Polignac number, because 20420157 - 2¹² = 20416061 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 (20420107) 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, 42844 + ... + 43317.

It is an arithmetic number, because the mean of its divisors is an integer number (3446480).

Almost surely, 2^20420157 is an apocalyptic number.

It is an amenable number.

20420157 is a deficient number, since it is larger than the sum of its proper divisors (7151683).

20420157 is an equidigital number, since it uses as much as digits as its factorization.

20420157 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 86243.

The product of its (nonzero) digits is 560, while the sum is 21.

The square root of 20420157 is about 4518.8667827233. The cubic root of 20420157 is about 273.3294068773.

Adding to 20420157 its reverse (75102402), we get a palindrome (95522559).

The spelling of 20420157 in words is "twenty million, four hundred twenty thousand, one hundred fifty-seven".