1216261200 has 240 divisors, whose sum is σ = 4857831936. Its totient is φ = 252710400.

The previous prime is 1216261177. The next prime is 1216261217. The reversal of 1216261200 is 21626121.

It is a tau number, because it is divible by the number of its divisors (240).

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 85819 + ... + 98981.

Almost surely, 2^1216261200 is an apocalyptic number.

1216261200 is a gapful number since it is divisible by the number (10) 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 1216261200, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2428915968).

1216261200 is an abundant number, since it is smaller than the sum of its proper divisors (3641570736).

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

1216261200 is a wasteful number, since it uses less digits than its factorization.

1216261200 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13202 (or 13191 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 21.

The square root of 1216261200 is about 34874.9365590821. The cubic root of 1216261200 is about 1067.4370779769.

Adding to 1216261200 its reverse (21626121), we get a palindrome (1237887321).

The spelling of 1216261200 in words is "one billion, two hundred sixteen million, two hundred sixty-one thousand, two hundred".