201221501401 has 4 divisors (see below), whose sum is σ = 201947933092. Its totient is φ = 200495069712.

The previous prime is 201221501359. The next prime is 201221501407. The reversal of 201221501401 is 104105122102.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 104105122102 = 2 ⋅52052561051.

It can be written as a sum of positive squares in 2 ways, for example, as 26969522176 + 174251979225 = 164224^2 + 417435^2 .

It is a cyclic number.

It is not a de Polignac number, because 201221501401 - 2³⁷ = 63782547929 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (201221501407) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 363215430 + ... + 363215983.

It is an arithmetic number, because the mean of its divisors is an integer number (50486983273).

Almost surely, 2^201221501401 is an apocalyptic number.

It is an amenable number.

201221501401 is a deficient number, since it is larger than the sum of its proper divisors (726431691).

201221501401 is an equidigital number, since it uses as much as digits as its factorization.

201221501401 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 726431690.

The product of its (nonzero) digits is 160, while the sum is 19.

Adding to 201221501401 its reverse (104105122102), we get a palindrome (305326623503).

The spelling of 201221501401 in words is "two hundred one billion, two hundred twenty-one million, five hundred one thousand, four hundred one".