1661211112 has 16 divisors (see below), whose sum is σ = 3397932000. Its totient is φ = 755095920.

The previous prime is 1661211067. The next prime is 1661211119. The reversal of 1661211112 is 2111121661.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (22).

It is not an unprimeable number, because it can be changed into a prime (1661211119) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9438612 + ... + 9438787.

It is an arithmetic number, because the mean of its divisors is an integer number (212370750).

Almost surely, 2^1661211112 is an apocalyptic number.

It is an amenable number.

1661211112 is an abundant number, since it is smaller than the sum of its proper divisors (1736720888).

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

1661211112 is a wasteful number, since it uses less digits than its factorization.

1661211112 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18877416 (or 18877412 counting only the distinct ones).

The product of its digits is 144, while the sum is 22.

The square root of 1661211112 is about 40757.9576524634. The cubic root of 1661211112 is about 1184.3360323453.

Adding to 1661211112 its reverse (2111121661), we get a palindrome (3772332773).

The spelling of 1661211112 in words is "one billion, six hundred sixty-one million, two hundred eleven thousand, one hundred twelve".