1217252591 has 4 divisors (see below), whose sum is σ = 1217813400. Its totient is φ = 1216691784.

The previous prime is 1217252579. The next prime is 1217252593. The reversal of 1217252591 is 1952527121.

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 1217252591 - 2⁶ = 1217252527 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 (1217252593) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 277136 + ... + 281493.

It is an arithmetic number, because the mean of its divisors is an integer number (304453350).

Almost surely, 2^1217252591 is an apocalyptic number.

1217252591 is a deficient number, since it is larger than the sum of its proper divisors (560809).

1217252591 is an equidigital number, since it uses as much as digits as its factorization.

1217252591 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 560808.

The product of its digits is 12600, while the sum is 35.

The square root of 1217252591 is about 34889.1471807495. The cubic root of 1217252591 is about 1067.7270266907.

The spelling of 1217252591 in words is "one billion, two hundred seventeen million, two hundred fifty-two thousand, five hundred ninety-one".