21655212564203 has 16 divisors (see below), whose sum is σ = 21768941508096. Its totient is φ = 21541800661920.

The previous prime is 21655212564187. The next prime is 21655212564221. The reversal of 21655212564203 is 30246521255612.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 21655212564203 - 2⁴ = 21655212564187 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21655212560203) 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, 611590526 + ... + 611625932.

It is an arithmetic number, because the mean of its divisors is an integer number (1360558844256).

Almost surely, 2^{21655212564203} is an apocalyptic number.

21655212564203 is a deficient number, since it is larger than the sum of its proper divisors (113728943893).

21655212564203 is a wasteful number, since it uses less digits than its factorization.

21655212564203 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 39794.

The product of its (nonzero) digits is 864000, while the sum is 44.

The spelling of 21655212564203 in words is "twenty-one trillion, six hundred fifty-five billion, two hundred twelve million, five hundred sixty-four thousand, two hundred three".