221520868161 has 8 divisors (see below), whose sum is σ = 296237601504. Its totient is φ = 147242356800.

The previous prime is 221520868157. The next prime is 221520868181. The reversal of 221520868161 is 161868025122.

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

It is not a de Polignac number, because 221520868161 - 2² = 221520868157 is a prime.

It is a Smith number, since the sum of its digits (42) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is not an unprimeable number, because it can be changed into a prime (221520868141) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 109554315 + ... + 109556336.

It is an arithmetic number, because the mean of its divisors is an integer number (37029700188).

Almost surely, 2^221520868161 is an apocalyptic number.

It is an amenable number.

221520868161 is a deficient number, since it is larger than the sum of its proper divisors (74716733343).

221520868161 is a wasteful number, since it uses less digits than its factorization.

221520868161 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 219110991.

The product of its (nonzero) digits is 92160, while the sum is 42.

The spelling of 221520868161 in words is "two hundred twenty-one billion, five hundred twenty million, eight hundred sixty-eight thousand, one hundred sixty-one".