21603217746655 has 8 divisors (see below), whose sum is σ = 25924618027152. Its totient is φ = 17282069709888.

The previous prime is 21603217746581. The next prime is 21603217746703. The reversal of 21603217746655 is 55664771230612.

It is a happy number.

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 21603217746655 - 2²¹ = 21603215649503 is a prime.

It is a super-3 number, since 3×21603217746655³ (a number of 41 digits) contains 333 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21603217746596 and 21603217746605.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 62872462 + ... + 63215131.

It is an arithmetic number, because the mean of its divisors is an integer number (3240577253394).

Almost surely, 2^{21603217746655} is an apocalyptic number.

21603217746655 is a deficient number, since it is larger than the sum of its proper divisors (4321400280497).

21603217746655 is a wasteful number, since it uses less digits than its factorization.

21603217746655 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 126121865.

The product of its (nonzero) digits is 12700800, while the sum is 55.

The spelling of 21603217746655 in words is "twenty-one trillion, six hundred three billion, two hundred seventeen million, seven hundred forty-six thousand, six hundred fifty-five".