1221175171601 has 16 divisors (see below), whose sum is σ = 1571617148928. Its totient is φ = 920869419600.

The previous prime is 1221175171561. The next prime is 1221175171609. The reversal of 1221175171601 is 1061715711221.

It is a cyclic number.

It is not a de Polignac number, because 1221175171601 - 2²² = 1221170977297 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (1221175171609) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 255794675 + ... + 255799448.

It is an arithmetic number, because the mean of its divisors is an integer number (98226071808).

Almost surely, 2^{1221175171601} is an apocalyptic number.

1221175171601 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1221175171601 is a deficient number, since it is larger than the sum of its proper divisors (350441977327).

1221175171601 is a wasteful number, since it uses less digits than its factorization.

1221175171601 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 511594172.

The product of its (nonzero) digits is 5880, while the sum is 35.

The spelling of 1221175171601 in words is "one trillion, two hundred twenty-one billion, one hundred seventy-five million, one hundred seventy-one thousand, six hundred one".