21301001 has 4 divisors (see below), whose sum is σ = 21512004. Its totient is φ = 21090000.

The previous prime is 21300997. The next prime is 21301031. The reversal of 21301001 is 10010312.

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 16613776 + 4687225 = 4076^2 + 2165^2 .

It is a cyclic number.

It is not a de Polignac number, because 21301001 - 2² = 21300997 is a prime.

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 21301001.

It is not an unprimeable number, because it can be changed into a prime (21301031) 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, 105350 + ... + 105551.

It is an arithmetic number, because the mean of its divisors is an integer number (5378001).

Almost surely, 2^21301001 is an apocalyptic number.

It is an amenable number.

21301001 is a deficient number, since it is larger than the sum of its proper divisors (211003).

21301001 is a wasteful number, since it uses less digits than its factorization.

21301001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 211002.

The product of its (nonzero) digits is 6, while the sum is 8.

The square root of 21301001 is about 4615.3007485970. The cubic root of 21301001 is about 277.2043264728.

Adding to 21301001 its reverse (10010312), we get a palindrome (31311313).

The spelling of 21301001 in words is "twenty-one million, three hundred one thousand, one".