1211611616 has 12 divisors (see below), whose sum is σ = 2385360432. Its totient is φ = 605805792.

The previous prime is 1211611601. The next prime is 1211611631. The reversal of 1211611616 is 6161161121.

It is an interprime number because it is at equal distance from previous prime (1211611601) and next prime (1211611631).

It is a super-2 number, since 2×1211611616² = 2936005416052262912, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 18931400 + ... + 18931463.

It is an arithmetic number, because the mean of its divisors is an integer number (198780036).

Almost surely, 2^1211611616 is an apocalyptic number.

1211611616 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

1211611616 is a deficient number, since it is larger than the sum of its proper divisors (1173748816).

1211611616 is an equidigital number, since it uses as much as digits as its factorization.

1211611616 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 37862873 (or 37862865 counting only the distinct ones).

The product of its digits is 432, while the sum is 26.

The square root of 1211611616 is about 34808.2119046641. The cubic root of 1211611616 is about 1066.0751237439.

Adding to 1211611616 its reverse (6161161121), we get a palindrome (7372772737).

It can be divided in two parts, 12116 and 11616, that added together give a palindrome (23732).

The spelling of 1211611616 in words is "one billion, two hundred eleven million, six hundred eleven thousand, six hundred sixteen".