1216861242 has 16 divisors (see below), whose sum is σ = 2439983520. Its totient is φ = 404576912.

The previous prime is 1216861201. The next prime is 1216861307. The reversal of 1216861242 is 2421686121.

It is a happy number.

It is a super-3 number, since 3×1216861242³ (a number of 28 digits) contains 333 as substring.

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, 258348 + ... + 263015.

It is an arithmetic number, because the mean of its divisors is an integer number (152498970).

Almost surely, 2^1216861242 is an apocalyptic number.

1216861242 is an abundant number, since it is smaller than the sum of its proper divisors (1223122278).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1216861242 is a wasteful number, since it uses less digits than its factorization.

1216861242 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 521757.

The product of its digits is 9216, while the sum is 33.

The square root of 1216861242 is about 34883.5382666380. The cubic root of 1216861242 is about 1067.6125890093.

The spelling of 1216861242 in words is "one billion, two hundred sixteen million, eight hundred sixty-one thousand, two hundred forty-two".