1817918121 has 8 divisors (see below), whose sum is σ = 2424463840. Its totient is φ = 1211658912.

The previous prime is 1817918111. The next prime is 1817918131. The reversal of 1817918121 is 1218197181.

It is an interprime number because it is at equal distance from previous prime (1817918111) and next prime (1817918131).

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 1817918121 - 2⁶ = 1817918057 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1817918121.

It is not an unprimeable number, because it can be changed into a prime (1817918101) 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 7 ways as a sum of consecutive naturals, for example, 56356 + ... + 82533.

It is an arithmetic number, because the mean of its divisors is an integer number (303057980).

Almost surely, 2^1817918121 is an apocalyptic number.

It is an amenable number.

1817918121 is a deficient number, since it is larger than the sum of its proper divisors (606545719).

1817918121 is a wasteful number, since it uses less digits than its factorization.

1817918121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 143255.

The product of its digits is 8064, while the sum is 39.

The square root of 1817918121 is about 42637.0510354551. The cubic root of 1817918121 is about 1220.4634360905.

The spelling of 1817918121 in words is "one billion, eight hundred seventeen million, nine hundred eighteen thousand, one hundred twenty-one".