21201001 has 8 divisors (see below), whose sum is σ = 22305600. Its totient is φ = 20121360.

The previous prime is 21200987. The next prime is 21201031. The reversal of 21201001 is 10010212.

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

It is not a de Polignac number, because 21201001 - 2¹¹ = 21198953 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21201031) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4485 + ... + 7906.

It is an arithmetic number, because the mean of its divisors is an integer number (2788200).

Almost surely, 2^21201001 is an apocalyptic number.

It is an amenable number.

21201001 is a deficient number, since it is larger than the sum of its proper divisors (1104599).

21201001 is a wasteful number, since it uses less digits than its factorization.

21201001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12479.

The product of its (nonzero) digits is 4, while the sum is 7.

The square root of 21201001 is about 4604.4544736592. The cubic root of 21201001 is about 276.7698566708.

Adding to 21201001 its reverse (10010212), we get a palindrome (31211213).

The spelling of 21201001 in words is "twenty-one million, two hundred one thousand, one".