21420446206 has 8 divisors (see below), whose sum is σ = 32131828800. Its totient is φ = 10709836608.

The previous prime is 21420446197. The next prime is 21420446207. The reversal of 21420446206 is 60264402412.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21420446207) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 118131 + ... + 238318.

It is an arithmetic number, because the mean of its divisors is an integer number (4016478600).

Almost surely, 2^21420446206 is an apocalyptic number.

21420446206 is a deficient number, since it is larger than the sum of its proper divisors (10711382594).

21420446206 is a wasteful number, since it uses less digits than its factorization.

21420446206 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 386498.

The product of its (nonzero) digits is 18432, while the sum is 31.

Adding to 21420446206 its reverse (60264402412), we get a palindrome (81684848618).

The spelling of 21420446206 in words is "twenty-one billion, four hundred twenty million, four hundred forty-six thousand, two hundred six".