20489477 has 2 divisors, whose sum is σ = 20489478. Its totient is φ = 20489476.

The previous prime is 20489431. The next prime is 20489479. The reversal of 20489477 is 77498402.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 15476356 + 5013121 = 3934^2 + 2239^2 .

It is a cyclic number.

It is not a de Polignac number, because 20489477 - 2⁸ = 20489221 is a prime.

Together with 20489479, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20489479) by changing a digit.

It is a good prime.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10244738 + 10244739.

It is an arithmetic number, because the mean of its divisors is an integer number (10244739).

Almost surely, 2^20489477 is an apocalyptic number.

It is an amenable number.

20489477 is a deficient number, since it is larger than the sum of its proper divisors (1).

20489477 is an equidigital number, since it uses as much as digits as its factorization.

20489477 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 112896, while the sum is 41.

The square root of 20489477 is about 4526.5303489538. The cubic root of 20489477 is about 273.6383466324.

The spelling of 20489477 in words is "twenty million, four hundred eighty-nine thousand, four hundred seventy-seven".