21317666001 has 32 divisors (see below), whose sum is σ = 30395917440. Its totient is φ = 13242921984.

The previous prime is 21317665987. The next prime is 21317666009. The reversal of 21317666001 is 10066671312.

It is not a de Polignac number, because 21317666001 - 2⁹ = 21317665489 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21317666009) by changing a digit.

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 31 ways as a sum of consecutive naturals, for example, 2231431 + ... + 2240963.

It is an arithmetic number, because the mean of its divisors is an integer number (949872420).

Almost surely, 2^21317666001 is an apocalyptic number.

It is an amenable number.

21317666001 is a deficient number, since it is larger than the sum of its proper divisors (9078251439).

21317666001 is a wasteful number, since it uses less digits than its factorization.

21317666001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9985.

The product of its (nonzero) digits is 9072, while the sum is 33.

The spelling of 21317666001 in words is "twenty-one billion, three hundred seventeen million, six hundred sixty-six thousand, one".