20571011 has 4 divisors (see below), whose sum is σ = 21234624. Its totient is φ = 19907400.

The previous prime is 20570989. The next prime is 20571013. The reversal of 20571011 is 11017502.

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

It is a cyclic number.

It is not a de Polignac number, because 20571011 - 2¹⁴ = 20554627 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20571013) 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 in 3 ways as a sum of consecutive naturals, for example, 331760 + ... + 331821.

It is an arithmetic number, because the mean of its divisors is an integer number (5308656).

Almost surely, 2^20571011 is an apocalyptic number.

20571011 is a deficient number, since it is larger than the sum of its proper divisors (663613).

20571011 is an equidigital number, since it uses as much as digits as its factorization.

20571011 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 663612.

The product of its (nonzero) digits is 70, while the sum is 17.

The square root of 20571011 is about 4535.5276429540. The cubic root of 20571011 is about 274.0008302673. Note that the first 3 decimals are identical.

Adding to 20571011 its reverse (11017502), we get a palindrome (31588513).

The spelling of 20571011 in words is "twenty million, five hundred seventy-one thousand, eleven".