20420137 has 4 divisors (see below), whose sum is σ = 20854656. Its totient is φ = 19985620.

The previous prime is 20420129. The next prime is 20420167. The reversal of 20420137 is 73102402.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 20420137 - 2³ = 20420129 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20420107) 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 3 ways as a sum of consecutive naturals, for example, 217189 + ... + 217282.

It is an arithmetic number, because the mean of its divisors is an integer number (5213664).

Almost surely, 2^20420137 is an apocalyptic number.

It is an amenable number.

20420137 is a deficient number, since it is larger than the sum of its proper divisors (434519).

20420137 is an equidigital number, since it uses as much as digits as its factorization.

20420137 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 434518.

The product of its (nonzero) digits is 336, while the sum is 19.

The square root of 20420137 is about 4518.8645697786. The cubic root of 20420137 is about 273.3293176421.

Adding to 20420137 its reverse (73102402), we get a palindrome (93522539).

The spelling of 20420137 in words is "twenty million, four hundred twenty thousand, one hundred thirty-seven".