2218121957 has 8 divisors (see below), whose sum is σ = 2225691000. Its totient is φ = 2210563264.

The previous prime is 2218121923. The next prime is 2218121981. The reversal of 2218121957 is 7591218122.

2218121957 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 845123041 + 1372998916 = 29071^2 + 37054^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 2218121957 - 2²⁴ = 2201344741 is a prime.

It is a super-2 number, since 2×2218121957² = 9840130032251019698, which contains 22 as substring.

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 2218121957.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2218121557) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 868919 + ... + 871467.

It is an arithmetic number, because the mean of its divisors is an integer number (278211375).

Almost surely, 2^2218121957 is an apocalyptic number.

It is an amenable number.

2218121957 is a deficient number, since it is larger than the sum of its proper divisors (7569043).

2218121957 is a wasteful number, since it uses less digits than its factorization.

2218121957 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5175.

The product of its digits is 20160, while the sum is 38.

The square root of 2218121957 is about 47096.9421194200. The cubic root of 2218121957 is about 1304.1527864703.

The spelling of 2218121957 in words is "two billion, two hundred eighteen million, one hundred twenty-one thousand, nine hundred fifty-seven".