1817121242 has 4 divisors (see below), whose sum is σ = 2725681866. Its totient is φ = 908560620.

The previous prime is 1817121223. The next prime is 1817121263. The reversal of 1817121242 is 2421217181.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 2421217181 = 11149 ⋅217169.

It can be written as a sum of positive squares in only one way, i.e., 1726319401 + 90801841 = 41549^2 + 9529^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 454280309 + ... + 454280312.

Almost surely, 2^1817121242 is an apocalyptic number.

1817121242 is a deficient number, since it is larger than the sum of its proper divisors (908560624).

1817121242 is an equidigital number, since it uses as much as digits as its factorization.

1817121242 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 908560623.

The product of its digits is 1792, while the sum is 29.

The square root of 1817121242 is about 42627.7050989143. The cubic root of 1817121242 is about 1220.2850811887.

The spelling of 1817121242 in words is "one billion, eight hundred seventeen million, one hundred twenty-one thousand, two hundred forty-two".