21121356440566 has 32 divisors (see below), whose sum is σ = 35057149023168. Its totient is φ = 9492927882240.

The previous prime is 21121356440501. The next prime is 21121356440603. The reversal of 21121356440566 is 66504465312112.

It is a super-2 number, since 2×21121356440566² (a number of 27 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (46).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 19913815 + ... + 20947618.

It is an arithmetic number, because the mean of its divisors is an integer number (1095535906974).

Almost surely, 2^{21121356440566} is an apocalyptic number.

21121356440566 is a deficient number, since it is larger than the sum of its proper divisors (13935792582602).

21121356440566 is a wasteful number, since it uses less digits than its factorization.

21121356440566 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40862136.

The product of its (nonzero) digits is 1036800, while the sum is 46.

The spelling of 21121356440566 in words is "twenty-one trillion, one hundred twenty-one billion, three hundred fifty-six million, four hundred forty thousand, five hundred sixty-six".