21661043534226 has 80 divisors (see below), whose sum is σ = 51098038833600. Its totient is φ = 6839434042272.

The previous prime is 21661043534213. The next prime is 21661043534233. The reversal of 21661043534226 is 62243534016612.

21661043534226 is a `hidden beast` number, since 2 + 1 + 6 + 6 + 104 + 3 + 534 + 2 + 2 + 6 = 666.

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 39 ways as a sum of consecutive naturals, for example, 23253040 + ... + 24166628.

It is an arithmetic number, because the mean of its divisors is an integer number (638725485420).

Almost surely, 2^{21661043534226} is an apocalyptic number.

21661043534226 is an abundant number, since it is smaller than the sum of its proper divisors (29436995299374).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21661043534226 is a wasteful number, since it uses less digits than its factorization.

21661043534226 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 921325 (or 921316 counting only the distinct ones).

The product of its (nonzero) digits is 1244160, while the sum is 45.

The spelling of 21661043534226 in words is "twenty-one trillion, six hundred sixty-one billion, forty-three million, five hundred thirty-four thousand, two hundred twenty-six".