1661123436 has 96 divisors (see below), whose sum is σ = 4594437120. Its totient is φ = 457208064.

The previous prime is 1661123417. The next prime is 1661123447. The reversal of 1661123436 is 6343211661.

It is a nude number because it is divisible by every one of its digits.

It is a junction number, because it is equal to n+sod(n) for n = 1661123397 and 1661123406.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 317530 + ... + 322718.

It is an arithmetic number, because the mean of its divisors is an integer number (47858720).

Almost surely, 2^1661123436 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1661123436, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2297218560).

1661123436 is an abundant number, since it is smaller than the sum of its proper divisors (2933313684).

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

1661123436 is a wasteful number, since it uses less digits than its factorization.

1661123436 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5343 (or 5341 counting only the distinct ones).

The product of its digits is 15552, while the sum is 33.

The square root of 1661123436 is about 40756.8820691672. The cubic root of 1661123436 is about 1184.3151962071.

The spelling of 1661123436 in words is "one billion, six hundred sixty-one million, one hundred twenty-three thousand, four hundred thirty-six".