20575551 has 4 divisors (see below), whose sum is σ = 27434072. Its totient is φ = 13717032.

The previous prime is 20575523. The next prime is 20575567. The reversal of 20575551 is 15557502.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 20575551 - 2⁶ = 20575487 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20575571) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3429256 + ... + 3429261.

It is an arithmetic number, because the mean of its divisors is an integer number (6858518).

Almost surely, 2^20575551 is an apocalyptic number.

20575551 is a deficient number, since it is larger than the sum of its proper divisors (6858521).

20575551 is an equidigital number, since it uses as much as digits as its factorization.

20575551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6858520.

The product of its (nonzero) digits is 8750, while the sum is 30.

The square root of 20575551 is about 4536.0281083785. The cubic root of 20575551 is about 274.0209860140.

The spelling of 20575551 in words is "twenty million, five hundred seventy-five thousand, five hundred fifty-one".