21655500201601 has 8 divisors (see below), whose sum is σ = 24877376991104. Its totient is φ = 18465681888000.

The previous prime is 21655500201479. The next prime is 21655500201607. The reversal of 21655500201601 is 10610200555612.

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 21655500201601 - 2³⁵ = 21621140463233 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21655500201607) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8014617525 + ... + 8014620226.

It is an arithmetic number, because the mean of its divisors is an integer number (3109672123888).

Almost surely, 2^{21655500201601} is an apocalyptic number.

It is an amenable number.

21655500201601 is a deficient number, since it is larger than the sum of its proper divisors (3221876789503).

21655500201601 is a wasteful number, since it uses less digits than its factorization.

21655500201601 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16029237951.

The product of its (nonzero) digits is 18000, while the sum is 34.

The spelling of 21655500201601 in words is "twenty-one trillion, six hundred fifty-five billion, five hundred million, two hundred one thousand, six hundred one".