1217540771 has 4 divisors (see below), whose sum is σ = 1220205432. Its totient is φ = 1214876112.

The previous prime is 1217540749. The next prime is 1217540773. The reversal of 1217540771 is 1770457121.

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

It is a cyclic number.

It is not a de Polignac number, because 1217540771 - 2⁶ = 1217540707 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1217540773) 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, 1331645 + ... + 1332558.

It is an arithmetic number, because the mean of its divisors is an integer number (305051358).

Almost surely, 2^1217540771 is an apocalyptic number.

1217540771 is a deficient number, since it is larger than the sum of its proper divisors (2664661).

1217540771 is an equidigital number, since it uses as much as digits as its factorization.

1217540771 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2664660.

The product of its (nonzero) digits is 13720, while the sum is 35.

The square root of 1217540771 is about 34893.2768739194. The cubic root of 1217540771 is about 1067.8112801694.

Adding to 1217540771 its reverse (1770457121), we get a palindrome (2987997892).

The spelling of 1217540771 in words is "one billion, two hundred seventeen million, five hundred forty thousand, seven hundred seventy-one".