21179517460 has 24 divisors (see below), whose sum is σ = 44687786976. Its totient is φ = 8431654560.

The previous prime is 21179517451. The next prime is 21179517487. The reversal of 21179517460 is 6471597112.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 2505202 + ... + 2513641.

It is an arithmetic number, because the mean of its divisors is an integer number (1861991124).

Almost surely, 2^21179517460 is an apocalyptic number.

21179517460 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21179517460 is an abundant number, since it is smaller than the sum of its proper divisors (23508269516).

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

21179517460 is a wasteful number, since it uses less digits than its factorization.

21179517460 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5019063 (or 5019061 counting only the distinct ones).

The product of its (nonzero) digits is 105840, while the sum is 43.

The spelling of 21179517460 in words is "twenty-one billion, one hundred seventy-nine million, five hundred seventeen thousand, four hundred sixty".