21355201001 has 8 divisors (see below), whose sum is σ = 21894145224. Its totient is φ = 20817118080.

The previous prime is 21355200949. The next prime is 21355201027. The reversal of 21355201001 is 10010255312.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 475240000 + 20879961001 = 21800^2 + 144499^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21355201001 - 2³⁴ = 4175331817 is a prime.

It is a super-2 number, since 2×21355201001² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21355201051) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 164966 + ... + 264431.

It is an arithmetic number, because the mean of its divisors is an integer number (2736768153).

Almost surely, 2^21355201001 is an apocalyptic number.

It is an amenable number.

21355201001 is a deficient number, since it is larger than the sum of its proper divisors (538944223).

21355201001 is a wasteful number, since it uses less digits than its factorization.

21355201001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 430651.

The product of its (nonzero) digits is 300, while the sum is 20.

Adding to 21355201001 its reverse (10010255312), we get a palindrome (31365456313).

The spelling of 21355201001 in words is "twenty-one billion, three hundred fifty-five million, two hundred one thousand, one".