21603265556761 has 8 divisors (see below), whose sum is σ = 24713393445504. Its totient is φ = 18499124441760.

The previous prime is 21603265556693. The next prime is 21603265556827. The reversal of 21603265556761 is 16765556230612.

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 21603265556761 - 2¹³ = 21603265548569 is a prime.

It is a super-2 number, since 2×21603265556761² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21603265506761) 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, 1496685700 + ... + 1496700133.

It is an arithmetic number, because the mean of its divisors is an integer number (3089174180688).

Almost surely, 2^{21603265556761} is an apocalyptic number.

It is an amenable number.

21603265556761 is a deficient number, since it is larger than the sum of its proper divisors (3110127888743).

21603265556761 is a wasteful number, since it uses less digits than its factorization.

21603265556761 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2993386871.

The product of its (nonzero) digits is 13608000, while the sum is 55.

The spelling of 21603265556761 in words is "twenty-one trillion, six hundred three billion, two hundred sixty-five million, five hundred fifty-six thousand, seven hundred sixty-one".