20205487 has 2 divisors, whose sum is σ = 20205488. Its totient is φ = 20205486.

The previous prime is 20205481. The next prime is 20205517. The reversal of 20205487 is 78450202.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20205487 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20205481) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10102743 + 10102744.

It is an arithmetic number, because the mean of its divisors is an integer number (10102744).

Almost surely, 2^20205487 is an apocalyptic number.

20205487 is a deficient number, since it is larger than the sum of its proper divisors (1).

20205487 is an equidigital number, since it uses as much as digits as its factorization.

20205487 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4480, while the sum is 28.

The square root of 20205487 is about 4495.0513901401. The cubic root of 20205487 is about 272.3682251515.

Adding to 20205487 its reverse (78450202), we get a palindrome (98655689).

The spelling of 20205487 in words is "twenty million, two hundred five thousand, four hundred eighty-seven".