1211501216 has 48 divisors (see below), whose sum is σ = 2478084840. Its totient is φ = 582328320.

The previous prime is 1211501201. The next prime is 1211501219. The reversal of 1211501216 is 6121051121.

It can be written as a sum of positive squares in 4 ways, for example, as 936604816 + 274896400 = 30604^2 + 16580^2 .

It is not an unprimeable number, because it can be changed into a prime (1211501219) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 220940 + ... + 226356.

Almost surely, 2^1211501216 is an apocalyptic number.

1211501216 is a gapful number since it is divisible by the number (16) 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 1211501216, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1239042420).

1211501216 is an abundant number, since it is smaller than the sum of its proper divisors (1266583624).

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

1211501216 is a wasteful number, since it uses less digits than its factorization.

1211501216 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5697 (or 5689 counting only the distinct ones).

The product of its (nonzero) digits is 120, while the sum is 20.

The square root of 1211501216 is about 34806.6260358570. The cubic root of 1211501216 is about 1066.0427431067.

Adding to 1211501216 its reverse (6121051121), we get a palindrome (7332552337).

The spelling of 1211501216 in words is "one billion, two hundred eleven million, five hundred one thousand, two hundred sixteen".