1217751481 has 4 divisors (see below), whose sum is σ = 1219131472. Its totient is φ = 1216371492.

The previous prime is 1217751473. The next prime is 1217751523. The reversal of 1217751481 is 1841577121.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 1217751481 - 2³ = 1217751473 is a prime.

It is a super-2 number, since 2×1217751481² = 2965837338955386722, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1217751481.

It is not an unprimeable number, because it can be changed into a prime (1217751421) 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, 688671 + ... + 690436.

It is an arithmetic number, because the mean of its divisors is an integer number (304782868).

Almost surely, 2^1217751481 is an apocalyptic number.

It is an amenable number.

1217751481 is a deficient number, since it is larger than the sum of its proper divisors (1379991).

1217751481 is an equidigital number, since it uses as much as digits as its factorization.

1217751481 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1379990.

The product of its digits is 15680, while the sum is 37.

The square root of 1217751481 is about 34896.2960928520. The cubic root of 1217751481 is about 1067.8728757895.

It can be divided in two parts, 121775 and 1481, that added together give a triangular number (123256 = T₄₉₆).

The spelling of 1217751481 in words is "one billion, two hundred seventeen million, seven hundred fifty-one thousand, four hundred eighty-one".