1643553461 has 8 divisors (see below), whose sum is σ = 1795504800. Its totient is φ = 1492025040.

The previous prime is 1643553451. The next prime is 1643553469.

1643553461 is nontrivially palindromic in base 10.

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

It is not a de Polignac number, because 1643553461 - 2²² = 1639359157 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1643553469) 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 7 ways as a sum of consecutive naturals, for example, 97571 + ... + 113168.

It is an arithmetic number, because the mean of its divisors is an integer number (224438100).

Almost surely, 2^1643553461 is an apocalyptic number.

1643553461 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1643553461 is a deficient number, since it is larger than the sum of its proper divisors (151951339).

1643553461 is a wasteful number, since it uses less digits than its factorization.

1643553461 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 211459.

The product of its digits is 129600, while the sum is 38.

The square root of 1643553461 is about 40540.7629553268. The cubic root of 1643553461 is about 1180.1248218527.

It can be divided in two parts, 16435 and 53461, that added together give a palindrome (69896).

The spelling of 1643553461 in words is "one billion, six hundred forty-three million, five hundred fifty-three thousand, four hundred sixty-one".