1661798755 has 8 divisors (see below), whose sum is σ = 1994457024. Its totient is φ = 1329240000.

The previous prime is 1661798717. The next prime is 1661798759. The reversal of 1661798755 is 5578971661.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 1661798755 - 2¹³ = 1661790563 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1661798696 and 1661798705.

It is not an unprimeable number, because it can be changed into a prime (1661798759) 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 7 ways as a sum of consecutive naturals, for example, 18855 + ... + 60655.

It is an arithmetic number, because the mean of its divisors is an integer number (249307128).

Almost surely, 2^1661798755 is an apocalyptic number.

1661798755 is a deficient number, since it is larger than the sum of its proper divisors (332658269).

1661798755 is an equidigital number, since it uses as much as digits as its factorization.

1661798755 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 49757.

The product of its digits is 3175200, while the sum is 55.

The square root of 1661798755 is about 40765.1659508458. The cubic root of 1661798755 is about 1184.4756663600.

The spelling of 1661798755 in words is "one billion, six hundred sixty-one million, seven hundred ninety-eight thousand, seven hundred fifty-five".