21263243401 has 8 divisors (see below), whose sum is σ = 21333795840. Its totient is φ = 21192749952.

The previous prime is 21263243399. The next prime is 21263243447. The reversal of 21263243401 is 10434236212.

It is a happy number.

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 21263243401 - 2¹ = 21263243399 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 21263243401.

It is not an unprimeable number, because it can be changed into a prime (21263241401) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 776916 + ... + 803818.

It is an arithmetic number, because the mean of its divisors is an integer number (2666724480).

Almost surely, 2^21263243401 is an apocalyptic number.

It is an amenable number.

21263243401 is a deficient number, since it is larger than the sum of its proper divisors (70552439).

21263243401 is a wasteful number, since it uses less digits than its factorization.

21263243401 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29495.

The product of its (nonzero) digits is 6912, while the sum is 28.

Adding to 21263243401 its reverse (10434236212), we get a palindrome (31697479613).

The spelling of 21263243401 in words is "twenty-one billion, two hundred sixty-three million, two hundred forty-three thousand, four hundred one".