1661615112 has 64 divisors (see below), whose sum is σ = 4293921600. Its totient is φ = 535530240.

The previous prime is 1661615099. The next prime is 1661615119. The reversal of 1661615112 is 2115161661.

It is a self number, because there is not a number n which added to its sum of digits gives 1661615112.

It is not an unprimeable number, because it can be changed into a prime (1661615119) 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 15 ways as a sum of consecutive naturals, for example, 76758 + ... + 95994.

It is an arithmetic number, because the mean of its divisors is an integer number (67092525).

Almost surely, 2^1661615112 is an apocalyptic number.

1661615112 is a gapful number since it is divisible by the number (12) 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 1661615112, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2146960800).

1661615112 is an abundant number, since it is smaller than the sum of its proper divisors (2632306488).

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

1661615112 is a wasteful number, since it uses less digits than its factorization.

1661615112 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19366 (or 19362 counting only the distinct ones).

The product of its digits is 2160, while the sum is 30.

The square root of 1661615112 is about 40762.9134385657. The cubic root of 1661615112 is about 1184.4320331829.

Adding to 1661615112 its reverse (2115161661), we get a palindrome (3776776773).

The spelling of 1661615112 in words is "one billion, six hundred sixty-one million, six hundred fifteen thousand, one hundred twelve".