21000646317 has 32 divisors (see below), whose sum is σ = 33403189248. Its totient is φ = 11474882496.

The previous prime is 21000646313. The next prime is 21000646319. The reversal of 21000646317 is 71364600012.

It is not a de Polignac number, because 21000646317 - 2² = 21000646313 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21000646313) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2179803 + ... + 2189415.

It is an arithmetic number, because the mean of its divisors is an integer number (1043849664).

Almost surely, 2^21000646317 is an apocalyptic number.

It is an amenable number.

21000646317 is a deficient number, since it is larger than the sum of its proper divisors (12402542931).

21000646317 is a wasteful number, since it uses less digits than its factorization.

21000646317 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14169.

The product of its (nonzero) digits is 6048, while the sum is 30.

The spelling of 21000646317 in words is "twenty-one billion, six hundred forty-six thousand, three hundred seventeen".