1216556522 has 8 divisors (see below), whose sum is σ = 1874154756. Its totient is φ = 591838272.

The previous prime is 1216556513. The next prime is 1216556557. The reversal of 1216556522 is 2256556121.

It can be written as a sum of positive squares in 2 ways, for example, as 1216544641 + 11881 = 34879^2 + 109^2 .

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

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8219903 + ... + 8220050.

Almost surely, 2^1216556522 is an apocalyptic number.

1216556522 is a deficient number, since it is larger than the sum of its proper divisors (657598234).

1216556522 is a wasteful number, since it uses less digits than its factorization.

1216556522 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16439992.

The product of its digits is 36000, while the sum is 35.

The square root of 1216556522 is about 34879.1703169671. The cubic root of 1216556522 is about 1067.5234662576.

The spelling of 1216556522 in words is "one billion, two hundred sixteen million, five hundred fifty-six thousand, five hundred twenty-two".