21130501664 has 24 divisors (see below), whose sum is σ = 42305775120. Its totient is φ = 10386177856.

The previous prime is 21130501661. The next prime is 21130501729. The reversal of 21130501664 is 46610503112.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (21130501661) 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, 5594114 + ... + 5597889.

It is an arithmetic number, because the mean of its divisors is an integer number (1762740630).

Almost surely, 2^21130501664 is an apocalyptic number.

It is an amenable number.

21130501664 is an abundant number, since it is smaller than the sum of its proper divisors (21175273456).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21130501664 is a wasteful number, since it uses less digits than its factorization.

21130501664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11192072 (or 11192064 counting only the distinct ones).

The product of its (nonzero) digits is 4320, while the sum is 29.

The spelling of 21130501664 in words is "twenty-one billion, one hundred thirty million, five hundred one thousand, six hundred sixty-four".