1221516057166 has 8 divisors (see below), whose sum is σ = 1840275283320. Its totient is φ = 608090962728.

The previous prime is 1221516057137. The next prime is 1221516057169. The reversal of 1221516057166 is 6617506151221.

It is a happy number.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221516057169) 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 3 ways as a sum of consecutive naturals, for example, 1333532356 + ... + 1333533271.

It is an arithmetic number, because the mean of its divisors is an integer number (230034410415).

Almost surely, 2^{1221516057166} is an apocalyptic number.

1221516057166 is a deficient number, since it is larger than the sum of its proper divisors (618759226154).

1221516057166 is a wasteful number, since it uses less digits than its factorization.

1221516057166 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2667065858.

The product of its (nonzero) digits is 151200, while the sum is 43.

The spelling of 1221516057166 in words is "one trillion, two hundred twenty-one billion, five hundred sixteen million, fifty-seven thousand, one hundred sixty-six".