21551430064 has 60 divisors (see below), whose sum is σ = 42985497016. Its totient is φ = 10461782016.

The previous prime is 21551430059. The next prime is 21551430137. The reversal of 21551430064 is 46003415512.

It is a happy number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 37350544 + ... + 37351120.

Almost surely, 2^21551430064 is an apocalyptic number.

It is an amenable number.

21551430064 is a deficient number, since it is larger than the sum of its proper divisors (21434066952).

21551430064 is an equidigital number, since it uses as much as digits as its factorization.

21551430064 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1094 (or 855 counting only the distinct ones).

The product of its (nonzero) digits is 14400, while the sum is 31.

Adding to 21551430064 its reverse (46003415512), we get a palindrome (67554845576).

The spelling of 21551430064 in words is "twenty-one billion, five hundred fifty-one million, four hundred thirty thousand, sixty-four".