21655601123601 has 8 divisors (see below), whose sum is σ = 29019230987200. Its totient is φ = 14364519337872.

The previous prime is 21655601123587. The next prime is 21655601123609. The reversal of 21655601123601 is 10632110655612.

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

It is not a de Polignac number, because 21655601123601 - 2⁷ = 21655601123473 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21655601123601.

It is not an unprimeable number, because it can be changed into a prime (21655601123609) 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, 18137018770 + ... + 18137019963.

It is an arithmetic number, because the mean of its divisors is an integer number (3627403873400).

Almost surely, 2^{21655601123601} is an apocalyptic number.

It is an amenable number.

21655601123601 is a deficient number, since it is larger than the sum of its proper divisors (7363629863599).

21655601123601 is a wasteful number, since it uses less digits than its factorization.

21655601123601 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 36274038935.

The product of its (nonzero) digits is 64800, while the sum is 39.

The spelling of 21655601123601 in words is "twenty-one trillion, six hundred fifty-five billion, six hundred one million, one hundred twenty-three thousand, six hundred one".