201021240421 has 4 divisors (see below), whose sum is σ = 201285395244. Its totient is φ = 200757085600.

The previous prime is 201021240397. The next prime is 201021240473. The reversal of 201021240421 is 124042120102.

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

It can be written as a sum of positive squares in 2 ways, for example, as 10784822500 + 190236417921 = 103850^2 + 436161^2 .

It is a cyclic number.

It is not a de Polignac number, because 201021240421 - 2¹³ = 201021232229 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 (201021240521) 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, 132076270 + ... + 132077791.

It is an arithmetic number, because the mean of its divisors is an integer number (50321348811).

Almost surely, 2^201021240421 is an apocalyptic number.

It is an amenable number.

201021240421 is a deficient number, since it is larger than the sum of its proper divisors (264154823).

201021240421 is an equidigital number, since it uses as much as digits as its factorization.

201021240421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 264154822.

The product of its (nonzero) digits is 256, while the sum is 19.

Adding to 201021240421 its reverse (124042120102), we get a palindrome (325063360523).

The spelling of 201021240421 in words is "two hundred one billion, twenty-one million, two hundred forty thousand, four hundred twenty-one".