21432421013 has 4 divisors (see below), whose sum is σ = 21574357728. Its totient is φ = 21290484300.

The previous prime is 21432421009. The next prime is 21432421081. The reversal of 21432421013 is 31012423412.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21432421013 - 2² = 21432421009 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 21432421013.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21432421613) 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, 70968131 + ... + 70968432.

It is an arithmetic number, because the mean of its divisors is an integer number (5393589432).

Almost surely, 2^21432421013 is an apocalyptic number.

It is an amenable number.

21432421013 is a deficient number, since it is larger than the sum of its proper divisors (141936715).

21432421013 is a wasteful number, since it uses less digits than its factorization.

21432421013 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 141936714.

The product of its (nonzero) digits is 1152, while the sum is 23.

Adding to 21432421013 its reverse (31012423412), we get a palindrome (52444844425).

The spelling of 21432421013 in words is "twenty-one billion, four hundred thirty-two million, four hundred twenty-one thousand, thirteen".