1211511216 has 40 divisors (see below), whose sum is σ = 3131014384. Its totient is φ = 403672320.

The previous prime is 1211511209. The next prime is 1211511241. The reversal of 1211511216 is 6121151121.

It is a junction number, because it is equal to n+sod(n) for n = 1211511192 and 1211511201.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 189870 + ... + 196146.

Almost surely, 2^1211511216 is an apocalyptic number.

1211511216 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

1211511216 is an abundant number, since it is smaller than the sum of its proper divisors (1919503168).

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

1211511216 is a wasteful number, since it uses less digits than its factorization.

1211511216 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10309 (or 10303 counting only the distinct ones).

The product of its digits is 120, while the sum is 21.

The square root of 1211511216 is about 34806.7696863699. The cubic root of 1211511216 is about 1066.0456762165.

Adding to 1211511216 its reverse (6121151121), we get a palindrome (7332662337).

The spelling of 1211511216 in words is "one billion, two hundred eleven million, five hundred eleven thousand, two hundred sixteen".