1217929257 has 16 divisors (see below), whose sum is σ = 1805772480. Its totient is φ = 811308096.

The previous prime is 1217929213. The next prime is 1217929289. The reversal of 1217929257 is 7529297121.

It is not a de Polignac number, because 1217929257 - 2¹⁰ = 1217928233 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1217929157) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 18033 + ... + 52545.

It is an arithmetic number, because the mean of its divisors is an integer number (112860780).

Almost surely, 2^1217929257 is an apocalyptic number.

It is an amenable number.

1217929257 is a deficient number, since it is larger than the sum of its proper divisors (587843223).

1217929257 is a wasteful number, since it uses less digits than its factorization.

1217929257 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 35829 (or 35823 counting only the distinct ones).

The product of its digits is 158760, while the sum is 45.

The square root of 1217929257 is about 34898.8432043241. The cubic root of 1217929257 is about 1067.9248384803.

The spelling of 1217929257 in words is "one billion, two hundred seventeen million, nine hundred twenty-nine thousand, two hundred fifty-seven".