21687530946 has 16 divisors (see below), whose sum is σ = 43569571584. Its totient is φ = 7196758704.

The previous prime is 21687530933. The next prime is 21687530957. The reversal of 21687530946 is 64903578612.

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, 8103121 + ... + 8105796.

It is an arithmetic number, because the mean of its divisors is an integer number (2723098224).

It is a 2-persistent number, because it is pandigital, and so is 2⋅21687530946 = 43375061892, but 3⋅21687530946 = 65062592838 is not.

Almost surely, 2^21687530946 is an apocalyptic number.

21687530946 is an abundant number, since it is smaller than the sum of its proper divisors (21882040638).

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

21687530946 is a wasteful number, since it uses less digits than its factorization.

21687530946 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16209145.

The product of its (nonzero) digits is 2177280, while the sum is 51.

The spelling of 21687530946 in words is "twenty-one billion, six hundred eighty-seven million, five hundred thirty thousand, nine hundred forty-six".