21755064205501 has 16 divisors (see below), whose sum is σ = 23746004084160. Its totient is φ = 19766327339520.

The previous prime is 21755064205463. The next prime is 21755064205507. The reversal of 21755064205501 is 10550246055712.

It is a cyclic number.

It is not a de Polignac number, because 21755064205501 - 2³¹ = 21752916721853 is a prime.

It is a super-2 number, since 2×21755064205501² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21755064205507) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 268776205 + ... + 268857133.

It is an arithmetic number, because the mean of its divisors is an integer number (1484125255260).

Almost surely, 2^{21755064205501} is an apocalyptic number.

It is an amenable number.

21755064205501 is a deficient number, since it is larger than the sum of its proper divisors (1990939878659).

21755064205501 is a wasteful number, since it uses less digits than its factorization.

21755064205501 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 94236.

The product of its (nonzero) digits is 420000, while the sum is 43.

The spelling of 21755064205501 in words is "twenty-one trillion, seven hundred fifty-five billion, sixty-four million, two hundred five thousand, five hundred one".