2215218778 has 16 divisors (see below), whose sum is σ = 3528673920. Its totient is φ = 1040026176.

The previous prime is 2215218727. The next prime is 2215218781. The reversal of 2215218778 is 8778125122.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 253650 + ... + 262237.

It is an arithmetic number, because the mean of its divisors is an integer number (220542120).

Almost surely, 2^2215218778 is an apocalyptic number.

2215218778 is a deficient number, since it is larger than the sum of its proper divisors (1313455142).

2215218778 is a wasteful number, since it uses less digits than its factorization.

2215218778 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 516021.

The product of its digits is 125440, while the sum is 43.

The square root of 2215218778 is about 47066.1107167355. The cubic root of 2215218778 is about 1303.5835598747.

The spelling of 2215218778 in words is "two billion, two hundred fifteen million, two hundred eighteen thousand, seven hundred seventy-eight".