201021031231021 has 4 divisors (see below), whose sum is σ = 205695938934112. Its totient is φ = 196346123527932.

The previous prime is 201021031230991. The next prime is 201021031231063. The reversal of 201021031231021 is 120132130120102.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-201021031231021 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 201021031231021.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (201021031231721) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2337453851481 + ... + 2337453851566.

It is an arithmetic number, because the mean of its divisors is an integer number (51423984733528).

Almost surely, 2^{201021031231021} is an apocalyptic number.

It is an amenable number.

201021031231021 is a deficient number, since it is larger than the sum of its proper divisors (4674907703091).

201021031231021 is an equidigital number, since it uses as much as digits as its factorization.

201021031231021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4674907703090.

The product of its (nonzero) digits is 144, while the sum is 19.

Adding to 201021031231021 its reverse (120132130120102), we get a palindrome (321153161351123).

The spelling of 201021031231021 in words is "two hundred one trillion, twenty-one billion, thirty-one million, two hundred thirty-one thousand, twenty-one".