9251661791818 has 4 divisors (see below), whose sum is σ = 13877492687730. Its totient is φ = 4625830895908.

The previous prime is 9251661791783. The next prime is 9251661791819. The reversal of 9251661791818 is 8181971661529.

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

It can be written as a sum of positive squares in only one way, i.e., 7676152324569 + 1575509467249 = 2770587^2 + 1255193^2 .

It is a super-3 number, since 3×9251661791818³ (a number of 40 digits) contains 333 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 9251661791818.

It is not an unprimeable number, because it can be changed into a prime (9251661791819) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2312915447953 + ... + 2312915447956.

Almost surely, 2^{9251661791818} is an apocalyptic number.

9251661791818 is a deficient number, since it is larger than the sum of its proper divisors (4625830895912).

9251661791818 is a wasteful number, since it uses less digits than its factorization.

9251661791818 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4625830895911.

The product of its digits is 13063680, while the sum is 64.

The spelling of 9251661791818 in words is "nine trillion, two hundred fifty-one billion, six hundred sixty-one million, seven hundred ninety-one thousand, eight hundred eighteen".