1661049936 has 640 divisors, whose sum is σ = 6399590400. Its totient is φ = 400619520.

The previous prime is 1661049931. The next prime is 1661049937. The reversal of 1661049936 is 6399401661.

It is a junction number, because it is equal to n+sod(n) for n = 1661049891 and 1661049900.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1661049931) 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 127 ways as a sum of consecutive naturals, for example, 35341465 + ... + 35341511.

It is an arithmetic number, because the mean of its divisors is an integer number (9999360).

Almost surely, 2^1661049936 is an apocalyptic number.

1661049936 is a gapful number since it is divisible by the number (16) 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 1661049936, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3199795200).

1661049936 is an abundant number, since it is smaller than the sum of its proper divisors (4738540464).

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

1661049936 is a wasteful number, since it uses less digits than its factorization.

1661049936 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 144 (or 132 counting only the distinct ones).

The product of its (nonzero) digits is 209952, while the sum is 45.

The square root of 1661049936 is about 40755.9803709836. The cubic root of 1661049936 is about 1184.2977284201.

The spelling of 1661049936 in words is "one billion, six hundred sixty-one million, forty-nine thousand, nine hundred thirty-six".