21420230201 has 4 divisors (see below), whose sum is σ = 21528962532. Its totient is φ = 21311497872.

The previous prime is 21420230189. The next prime is 21420230263. The reversal of 21420230201 is 10203202412.

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 20851360000 + 568870201 = 144400^2 + 23851^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21420230201 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 21420230201.

It is not an unprimeable number, because it can be changed into a prime (21420230801) 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, 54365870 + ... + 54366263.

It is an arithmetic number, because the mean of its divisors is an integer number (5382240633).

Almost surely, 2^21420230201 is an apocalyptic number.

It is an amenable number.

21420230201 is a deficient number, since it is larger than the sum of its proper divisors (108732331).

21420230201 is a wasteful number, since it uses less digits than its factorization.

21420230201 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 108732330.

The product of its (nonzero) digits is 192, while the sum is 17.

Adding to 21420230201 its reverse (10203202412), we get a palindrome (31623432613).

The spelling of 21420230201 in words is "twenty-one billion, four hundred twenty million, two hundred thirty thousand, two hundred one".