221561072145 has 128 divisors (see below), whose sum is σ = 463976570880. Its totient is φ = 98195016960.

The previous prime is 221561072119. The next prime is 221561072167. The reversal of 221561072145 is 541270165122.

221561072145 is a `hidden beast` number, since 2 + 2 + 15 + 610 + 7 + 21 + 4 + 5 = 666.

It is not a de Polignac number, because 221561072145 - 2⁵ = 221561072113 is a prime.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 9883900 + ... + 9906290.

It is an arithmetic number, because the mean of its divisors is an integer number (3624816960).

Almost surely, 2^221561072145 is an apocalyptic number.

It is an amenable number.

221561072145 is an abundant number, since it is smaller than the sum of its proper divisors (242415498735).

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

221561072145 is a wasteful number, since it uses less digits than its factorization.

221561072145 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22732 (or 22726 counting only the distinct ones).

The product of its (nonzero) digits is 33600, while the sum is 36.

The spelling of 221561072145 in words is "two hundred twenty-one billion, five hundred sixty-one million, seventy-two thousand, one hundred forty-five".