1167645615221 has 4 divisors (see below), whose sum is σ = 1167648038700. Its totient is φ = 1167643191744.

The previous prime is 1167645615211. The next prime is 1167645615343. The reversal of 1167645615221 is 1225165467611.

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

It can be written as a sum of positive squares in 2 ways, for example, as 1043114968900 + 124530646321 = 1021330^2 + 352889^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1167645615221 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1167645615211) 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, 216626 + ... + 1543443.

It is an arithmetic number, because the mean of its divisors is an integer number (291912009675).

Almost surely, 2^{1167645615221} is an apocalyptic number.

It is an amenable number.

1167645615221 is a deficient number, since it is larger than the sum of its proper divisors (2423479).

1167645615221 is an equidigital number, since it uses as much as digits as its factorization.

1167645615221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2423478.

The product of its digits is 604800, while the sum is 47.

The spelling of 1167645615221 in words is "one trillion, one hundred sixty-seven billion, six hundred forty-five million, six hundred fifteen thousand, two hundred twenty-one".