20420901 has 12 divisors (see below), whose sum is σ = 30514380. Its totient is φ = 13144320.

The previous prime is 20420891. The next prime is 20420921. The reversal of 20420901 is 10902402.

It can be written as a sum of positive squares in 2 ways, for example, as 16524225 + 3896676 = 4065^2 + 1974^2 .

It is not a de Polignac number, because 20420901 - 2⁶ = 20420837 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20420921) 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 11 ways as a sum of consecutive naturals, for example, 38860 + ... + 39381.

It is an arithmetic number, because the mean of its divisors is an integer number (2542865).

Almost surely, 2^20420901 is an apocalyptic number.

It is an amenable number.

20420901 is a deficient number, since it is larger than the sum of its proper divisors (10093479).

20420901 is a wasteful number, since it uses less digits than its factorization.

20420901 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 78276 (or 78273 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 18.

The square root of 20420901 is about 4518.9491034974. The cubic root of 20420901 is about 273.3327263851.

It can be divided in two parts, 20420 and 901, that added together give a triangular number (21321 = T₂₀₆).

The spelling of 20420901 in words is "twenty million, four hundred twenty thousand, nine hundred one".