20428937 has 2 divisors, whose sum is σ = 20428938. Its totient is φ = 20428936.

The previous prime is 20428909. The next prime is 20428939. The reversal of 20428937 is 73982402.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19971961 + 456976 = 4469^2 + 676^2 .

It is a cyclic number.

It is not a de Polignac number, because 20428937 - 2¹² = 20424841 is a prime.

Together with 20428939, it forms a pair of twin primes.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 20428897 and 20428906.

It is not a weakly prime, because it can be changed into another prime (20428939) 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 as a sum of consecutive naturals, namely, 10214468 + 10214469.

It is an arithmetic number, because the mean of its divisors is an integer number (10214469).

Almost surely, 2^20428937 is an apocalyptic number.

It is an amenable number.

20428937 is a deficient number, since it is larger than the sum of its proper divisors (1).

20428937 is an equidigital number, since it uses as much as digits as its factorization.

20428937 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 24192, while the sum is 35.

The square root of 20428937 is about 4519.8381608195. The cubic root of 20428937 is about 273.3685755008.

The spelling of 20428937 in words is "twenty million, four hundred twenty-eight thousand, nine hundred thirty-seven".