21164054646 has 16 divisors (see below), whose sum is σ = 48374982144. Its totient is φ = 6046872744.

The previous prime is 21164054629. The next prime is 21164054719. The reversal of 21164054646 is 64645046112.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 251952990 + ... + 251953073.

It is an arithmetic number, because the mean of its divisors is an integer number (3023436384).

Almost surely, 2^21164054646 is an apocalyptic number.

21164054646 is an abundant number, since it is smaller than the sum of its proper divisors (27210927498).

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

21164054646 is a wasteful number, since it uses less digits than its factorization.

21164054646 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 503906075.

The product of its (nonzero) digits is 138240, while the sum is 39.

The spelling of 21164054646 in words is "twenty-one billion, one hundred sixty-four million, fifty-four thousand, six hundred forty-six".