20656523 has 2 divisors, whose sum is σ = 20656524. Its totient is φ = 20656522.

The previous prime is 20656511. The next prime is 20656529. The reversal of 20656523 is 32565602.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20656523 - 2¹⁸ = 20394379 is a prime.

It is not a weakly prime, because it can be changed into another prime (20656529) 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, 10328261 + 10328262.

It is an arithmetic number, because the mean of its divisors is an integer number (10328262).

Almost surely, 2^20656523 is an apocalyptic number.

20656523 is a deficient number, since it is larger than the sum of its proper divisors (1).

20656523 is an equidigital number, since it uses as much as digits as its factorization.

20656523 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 10800, while the sum is 29.

The square root of 20656523 is about 4544.9447741419. The cubic root of 20656523 is about 274.3799716999.

The spelling of 20656523 in words is "twenty million, six hundred fifty-six thousand, five hundred twenty-three".