1661688273 has 32 divisors (see below), whose sum is σ = 2687053824. Its totient is φ = 891677952.

The previous prime is 1661688271. The next prime is 1661688289. The reversal of 1661688273 is 3728861661.

It is not a de Polignac number, because 1661688273 - 2¹ = 1661688271 is a prime.

It is a super-2 number, since 2×1661688273² = 5522415833251445058, which contains 22 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (1661688271) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 161736 + ... + 171702.

It is an arithmetic number, because the mean of its divisors is an integer number (83970432).

Almost surely, 2^1661688273 is an apocalyptic number.

It is an amenable number.

1661688273 is a deficient number, since it is larger than the sum of its proper divisors (1025365551).

1661688273 is a wasteful number, since it uses less digits than its factorization.

1661688273 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10461.

The product of its digits is 580608, while the sum is 48.

The square root of 1661688273 is about 40763.8108252896. The cubic root of 1661688273 is about 1184.4494164625.

The spelling of 1661688273 in words is "one billion, six hundred sixty-one million, six hundred eighty-eight thousand, two hundred seventy-three".