21217016620801 has 8 divisors (see below), whose sum is σ = 21617407707840. Its totient is φ = 20816628127152.

The previous prime is 21217016620727. The next prime is 21217016620841. The reversal of 21217016620801 is 10802661071212.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21217016620801 - 2⁷ = 21217016620673 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21217016620841) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 26470990 + ... + 27260728.

It is an arithmetic number, because the mean of its divisors is an integer number (2702175963480).

Almost surely, 2^{21217016620801} is an apocalyptic number.

It is an amenable number.

21217016620801 is a deficient number, since it is larger than the sum of its proper divisors (400391087039).

21217016620801 is an equidigital number, since it uses as much as digits as its factorization.

21217016620801 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1296695.

The product of its (nonzero) digits is 16128, while the sum is 37.

The spelling of 21217016620801 in words is "twenty-one trillion, two hundred seventeen billion, sixteen million, six hundred twenty thousand, eight hundred one".