2218151261 has 4 divisors (see below), whose sum is σ = 2222392992. Its totient is φ = 2213909532.

The previous prime is 2218151251. The next prime is 2218151267. The reversal of 2218151261 is 1621518122.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 2218151261 - 2¹⁸ = 2217889117 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 (2218151267) 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, 2120081 + ... + 2121126.

It is an arithmetic number, because the mean of its divisors is an integer number (555598248).

Almost surely, 2^2218151261 is an apocalyptic number.

It is an amenable number.

2218151261 is a deficient number, since it is larger than the sum of its proper divisors (4241731).

2218151261 is an equidigital number, since it uses as much as digits as its factorization.

2218151261 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4241730.

The product of its digits is 1920, while the sum is 29.

The square root of 2218151261 is about 47097.2532213929. The cubic root of 2218151261 is about 1304.1585295757.

Adding to 2218151261 its reverse (1621518122), we get a palindrome (3839669383).

The spelling of 2218151261 in words is "two billion, two hundred eighteen million, one hundred fifty-one thousand, two hundred sixty-one".