21232421207 has 4 divisors (see below), whose sum is σ = 22349917080. Its totient is φ = 20114925336.

The previous prime is 21232421123. The next prime is 21232421237. The reversal of 21232421207 is 70212423212.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21232421207 is a prime.

It is a super-2 number, since 2×21232421207² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21232421237) 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 3 ways as a sum of consecutive naturals, for example, 558747908 + ... + 558747945.

It is an arithmetic number, because the mean of its divisors is an integer number (5587479270).

Almost surely, 2^21232421207 is an apocalyptic number.

21232421207 is a deficient number, since it is larger than the sum of its proper divisors (1117495873).

21232421207 is a wasteful number, since it uses less digits than its factorization.

21232421207 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1117495872.

The product of its (nonzero) digits is 2688, while the sum is 26.

Adding to 21232421207 its reverse (70212423212), we get a palindrome (91444844419).

The spelling of 21232421207 in words is "twenty-one billion, two hundred thirty-two million, four hundred twenty-one thousand, two hundred seven".