221666123146554 has 24 divisors (see below), whose sum is σ = 481543820746560. Its totient is φ = 73693750700808.

The previous prime is 221666123146529. The next prime is 221666123146579. The reversal of 221666123146554 is 455641321666122.

221666123146554 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (221666123146529) and next prime (221666123146579).

It is a self number, because there is not a number n which added to its sum of digits gives 221666123146554.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 16246410882 + ... + 16246424525.

It is an arithmetic number, because the mean of its divisors is an integer number (20064325864440).

Almost surely, 2^{221666123146554} is an apocalyptic number.

221666123146554 is an abundant number, since it is smaller than the sum of its proper divisors (259877697600006).

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

221666123146554 is a wasteful number, since it uses less digits than its factorization.

221666123146554 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32492835794 (or 32492835791 counting only the distinct ones).

The product of its digits is 12441600, while the sum is 54.

The spelling of 221666123146554 in words is "two hundred twenty-one trillion, six hundred sixty-six billion, one hundred twenty-three million, one hundred forty-six thousand, five hundred fifty-four".