20201020491 has 16 divisors (see below), whose sum is σ = 28584982944. Its totient is φ = 12645863424.

The previous prime is 20201020429. The next prime is 20201020577. The reversal of 20201020491 is 19402010202.

It is not a de Polignac number, because 20201020491 - 2¹⁹ = 20200496203 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20201020421) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 435306 + ... + 479471.

It is an arithmetic number, because the mean of its divisors is an integer number (1786561434).

Almost surely, 2^20201020491 is an apocalyptic number.

20201020491 is a deficient number, since it is larger than the sum of its proper divisors (8383962453).

20201020491 is a wasteful number, since it uses less digits than its factorization.

20201020491 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 915230.

The product of its (nonzero) digits is 288, while the sum is 21.

Adding to 20201020491 its reverse (19402010202), we get a palindrome (39603030693).

The spelling of 20201020491 in words is "twenty billion, two hundred one million, twenty thousand, four hundred ninety-one".