1217743320651 has 24 divisors (see below), whose sum is σ = 1917994867776. Its totient is φ = 681255001440.

The previous prime is 1217743320593. The next prime is 1217743320679. The reversal of 1217743320651 is 1560233477121.

It is not a de Polignac number, because 1217743320651 - 2⁶ = 1217743320587 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1217743320751) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 109169905 + ... + 109181058.

It is an arithmetic number, because the mean of its divisors is an integer number (79916452824).

Almost surely, 2^{1217743320651} is an apocalyptic number.

1217743320651 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

1217743320651 is a deficient number, since it is larger than the sum of its proper divisors (700251547125).

1217743320651 is a wasteful number, since it uses less digits than its factorization.

1217743320651 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 218351003 (or 218350990 counting only the distinct ones).

The product of its (nonzero) digits is 211680, while the sum is 42.

Adding to 1217743320651 its reverse (1560233477121), we get a palindrome (2777976797772).

The spelling of 1217743320651 in words is "one trillion, two hundred seventeen billion, seven hundred forty-three million, three hundred twenty thousand, six hundred fifty-one".