21420241001 has 4 divisors (see below), whose sum is σ = 21420607572. Its totient is φ = 21419874432.

The previous prime is 21420240997. The next prime is 21420241049. The reversal of 21420241001 is 10014202412.

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 10753482601 + 10666758400 = 103699^2 + 103280^2 .

It is a cyclic number.

It is not a de Polignac number, because 21420241001 - 2² = 21420240997 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21420241301) 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, 73856 + ... + 219761.

It is an arithmetic number, because the mean of its divisors is an integer number (5355151893).

Almost surely, 2^21420241001 is an apocalyptic number.

It is an amenable number.

21420241001 is a deficient number, since it is larger than the sum of its proper divisors (366571).

21420241001 is an equidigital number, since it uses as much as digits as its factorization.

21420241001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 366570.

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

Adding to 21420241001 its reverse (10014202412), we get a palindrome (31434443413).

The spelling of 21420241001 in words is "twenty-one billion, four hundred twenty million, two hundred forty-one thousand, one".