1661055100 has 36 divisors (see below), whose sum is σ = 3624443368. Its totient is φ = 660744000.

The previous prime is 1661055083. The next prime is 1661055103. The reversal of 1661055100 is 15501661.

It is a Harshad number since it is a multiple of its sum of digits (25).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1661055103) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 27786 + ... + 63985.

Almost surely, 2^1661055100 is an apocalyptic number.

1661055100 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1661055100 is an abundant number, since it is smaller than the sum of its proper divisors (1963388268).

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

1661055100 is a wasteful number, since it uses less digits than its factorization.

1661055100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 91966 (or 91959 counting only the distinct ones).

The product of its (nonzero) digits is 900, while the sum is 25.

The square root of 1661055100 is about 40756.0437236001. The cubic root of 1661055100 is about 1184.2989556975.

Adding to 1661055100 its reverse (15501661), we get a palindrome (1676556761).

The spelling of 1661055100 in words is "one billion, six hundred sixty-one million, fifty-five thousand, one hundred".