21661225466066 has 32 divisors (see below), whose sum is σ = 36214222296960. Its totient is φ = 9656907906816.

The previous prime is 21661225466057. The next prime is 21661225466149. The reversal of 21661225466066 is 66066452216612.

It is a junction number, because it is equal to n+sod(n) for n = 21661225465999 and 21661225466017.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 91223891 + ... + 91461033.

It is an arithmetic number, because the mean of its divisors is an integer number (1131694446780).

Almost surely, 2^{21661225466066} is an apocalyptic number.

21661225466066 is a deficient number, since it is larger than the sum of its proper divisors (14552996830894).

21661225466066 is a wasteful number, since it uses less digits than its factorization.

21661225466066 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 378578.

The product of its (nonzero) digits is 7464960, while the sum is 53.

The spelling of 21661225466066 in words is "twenty-one trillion, six hundred sixty-one billion, two hundred twenty-five million, four hundred sixty-six thousand, sixty-six".