1221207171 has 8 divisors (see below), whose sum is σ = 1651209984. Its totient is φ = 802671240.

The previous prime is 1221207151. The next prime is 1221207179. The reversal of 1221207171 is 1717021221.

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

It is not a de Polignac number, because 1221207171 - 2³⁰ = 147465347 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1221207179) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2866471 + ... + 2866896.

It is an arithmetic number, because the mean of its divisors is an integer number (206401248).

Almost surely, 2^1221207171 is an apocalyptic number.

1221207171 is a deficient number, since it is larger than the sum of its proper divisors (430002813).

1221207171 is an equidigital number, since it uses as much as digits as its factorization.

1221207171 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5733441.

The product of its (nonzero) digits is 392, while the sum is 24.

The square root of 1221207171 is about 34945.7747231336. The cubic root of 1221207171 is about 1068.8820451467.

Adding to 1221207171 its reverse (1717021221), we get a palindrome (2938228392).

The spelling of 1221207171 in words is "one billion, two hundred twenty-one million, two hundred seven thousand, one hundred seventy-one".