1661646833 has 32 divisors (see below), whose sum is σ = 2118832128. Its totient is φ = 1265616000.

The previous prime is 1661646787. The next prime is 1661646851. The reversal of 1661646833 is 3386461661.

It is not a de Polignac number, because 1661646833 - 2⁶ = 1661646769 is a prime.

It is a super-2 number, since 2×1661646833² = 5522140395237859778, which contains 22 as substring.

It is a Smith number, since the sum of its digits (44) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is not an unprimeable number, because it can be changed into a prime (1661646853) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 705608 + ... + 707958.

It is an arithmetic number, because the mean of its divisors is an integer number (66213504).

Almost surely, 2^1661646833 is an apocalyptic number.

It is an amenable number.

1661646833 is a deficient number, since it is larger than the sum of its proper divisors (457185295).

1661646833 is a wasteful number, since it uses less digits than its factorization.

1661646833 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2573.

The product of its digits is 373248, while the sum is 44.

The square root of 1661646833 is about 40763.3025281318. The cubic root of 1661646833 is about 1184.4395702532.

The spelling of 1661646833 in words is "one billion, six hundred sixty-one million, six hundred forty-six thousand, eight hundred thirty-three".