21621555560226 has 8 divisors (see below), whose sum is σ = 43243111120464. Its totient is φ = 7207185186740.

The previous prime is 21621555560221. The next prime is 21621555560243. The reversal of 21621555560226 is 62206555512612.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

21621555560226 is an admirable number.

It is not an unprimeable number, because it can be changed into a prime (21621555560221) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1801796296680 + ... + 1801796296691.

It is an arithmetic number, because the mean of its divisors is an integer number (5405388890058).

Almost surely, 2^{21621555560226} is an apocalyptic number.

21621555560226 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

21621555560226 is a wasteful number, since it uses less digits than its factorization.

21621555560226 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3603592593376.

The product of its (nonzero) digits is 2160000, while the sum is 48.

The spelling of 21621555560226 in words is "twenty-one trillion, six hundred twenty-one billion, five hundred fifty-five million, five hundred sixty thousand, two hundred twenty-six".