221661545134127 has 4 divisors (see below), whose sum is σ = 253327480153296. Its totient is φ = 189995610114960.

The previous prime is 221661545134103. The next prime is 221661545134129. The reversal of 221661545134127 is 721431545166122.

221661545134127 is digitally balanced in base 2 and base 8, because in such bases it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 221661545134127 - 2¹⁶ = 221661545068591 is a prime.

It is a super-2 number, since 2×221661545134127² (a number of 29 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221661545134129) 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, 15832967509574 + ... + 15832967509587.

It is an arithmetic number, because the mean of its divisors is an integer number (63331870038324).

Almost surely, 2^{221661545134127} is an apocalyptic number.

221661545134127 is a deficient number, since it is larger than the sum of its proper divisors (31665935019169).

221661545134127 is an equidigital number, since it uses as much as digits as its factorization.

221661545134127 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31665935019168.

The product of its digits is 2419200, while the sum is 50.

The spelling of 221661545134127 in words is "two hundred twenty-one trillion, six hundred sixty-one billion, five hundred forty-five million, one hundred thirty-four thousand, one hundred twenty-seven".