1213831517 has 4 divisors (see below), whose sum is σ = 1230459420. Its totient is φ = 1197203616.

The previous prime is 1213831513. The next prime is 1213831547. The reversal of 1213831517 is 7151383121.

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

It can be written as a sum of positive squares in 2 ways, for example, as 753557401 + 460274116 = 27451^2 + 21454^2 .

It is a cyclic number.

It is not a de Polignac number, because 1213831517 - 2² = 1213831513 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 (1213831513) 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, 8313842 + ... + 8313987.

It is an arithmetic number, because the mean of its divisors is an integer number (307614855).

Almost surely, 2^1213831517 is an apocalyptic number.

It is an amenable number.

1213831517 is a deficient number, since it is larger than the sum of its proper divisors (16627903).

1213831517 is an equidigital number, since it uses as much as digits as its factorization.

1213831517 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16627902.

The product of its digits is 5040, while the sum is 32.

The square root of 1213831517 is about 34840.0849166589. The cubic root of 1213831517 is about 1066.7258100778.

The spelling of 1213831517 in words is "one billion, two hundred thirteen million, eight hundred thirty-one thousand, five hundred seventeen".