1216155552 has 24 divisors (see below), whose sum is σ = 3192408576. Its totient is φ = 405385152.

The previous prime is 1216155547. The next prime is 1216155559. The reversal of 1216155552 is 2555516121.

It is a tau number, because it is divible by the number of its divisors (24).

It is not an unprimeable number, because it can be changed into a prime (1216155559) 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, 6334048 + ... + 6334239.

It is an arithmetic number, because the mean of its divisors is an integer number (133017024).

Almost surely, 2^1216155552 is an apocalyptic number.

1216155552 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

1216155552 is an abundant number, since it is smaller than the sum of its proper divisors (1976253024).

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

1216155552 is a wasteful number, since it uses less digits than its factorization.

1216155552 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12668300 (or 12668292 counting only the distinct ones).

The product of its digits is 15000, while the sum is 33.

The square root of 1216155552 is about 34873.4218567665. The cubic root of 1216155552 is about 1067.4061701813.

The spelling of 1216155552 in words is "one billion, two hundred sixteen million, one hundred fifty-five thousand, five hundred fifty-two".