1216397952 has 384 divisors, whose sum is σ = 4562827200. Its totient is φ = 315463680.

The previous prime is 1216397947. The next prime is 1216397971. The reversal of 1216397952 is 2597936121.

It is a happy number.

1216397952 is a `hidden beast` number, since 1 + 2 + 1 + 639 + 7 + 9 + 5 + 2 = 666.

It is a tau number, because it is divible by the number of its divisors (384).

It is a junction number, because it is equal to n+sod(n) for n = 1216397898 and 1216397907.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1862458 + ... + 1863110.

Almost surely, 2^1216397952 is an apocalyptic number.

1216397952 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1216397952, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2281413600).

1216397952 is an abundant number, since it is smaller than the sum of its proper divisors (3346429248).

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

1216397952 is a wasteful number, since it uses less digits than its factorization.

1216397952 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 701 (or 676 counting only the distinct ones).

The product of its digits is 204120, while the sum is 45.

The square root of 1216397952 is about 34876.8971096914. The cubic root of 1216397952 is about 1067.4770827294.

The spelling of 1216397952 in words is "one billion, two hundred sixteen million, three hundred ninety-seven thousand, nine hundred fifty-two".