20506687 has 2 divisors, whose sum is σ = 20506688. Its totient is φ = 20506686.

The previous prime is 20506669. The next prime is 20506693. The reversal of 20506687 is 78660502.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20506687 - 2¹¹ = 20504639 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20506637) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10253343 + 10253344.

It is an arithmetic number, because the mean of its divisors is an integer number (10253344).

Almost surely, 2^20506687 is an apocalyptic number.

20506687 is a deficient number, since it is larger than the sum of its proper divisors (1).

20506687 is an equidigital number, since it uses as much as digits as its factorization.

20506687 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 20160, while the sum is 34.

The square root of 20506687 is about 4528.4309644732. The cubic root of 20506687 is about 273.7149387621.

The spelling of 20506687 in words is "twenty million, five hundred six thousand, six hundred eighty-seven".