21001242002201 has 4 divisors (see below), whose sum is σ = 21001419680292. Its totient is φ = 21001064324112.

The previous prime is 21001242002177. The next prime is 21001242002263. The reversal of 21001242002201 is 10220024210012.

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 9176749369225 + 11824492632976 = 3029315^2 + 3438676^2 .

It is a cyclic number.

It is not a de Polignac number, because 21001242002201 - 2²² = 21001237807897 is a prime.

It is a super-2 number, since 2×21001242002201² (a number of 27 digits) contains 22 as substring.

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 21001242002201.

It is not an unprimeable number, because it can be changed into a prime (21001242002281) 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, 88661630 + ... + 88898183.

It is an arithmetic number, because the mean of its divisors is an integer number (5250354920073).

Almost surely, 2^{21001242002201} is an apocalyptic number.

It is an amenable number.

21001242002201 is a deficient number, since it is larger than the sum of its proper divisors (177678091).

21001242002201 is a wasteful number, since it uses less digits than its factorization.

21001242002201 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 177678090.

The product of its (nonzero) digits is 128, while the sum is 17.

Adding to 21001242002201 its reverse (10220024210012), we get a palindrome (31221266212213).

The spelling of 21001242002201 in words is "twenty-one trillion, one billion, two hundred forty-two million, two thousand, two hundred one".