1645611133 has 4 divisors (see below), whose sum is σ = 1646745148. Its totient is φ = 1644477120.

The previous prime is 1645611089. The next prime is 1645611167. The reversal of 1645611133 is 3311165461.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 1260392004 + 385219129 = 35502^2 + 19627^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1645611133 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1645611095 and 1645611104.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1645611433) 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 3 ways as a sum of consecutive naturals, for example, 564828 + ... + 567733.

It is an arithmetic number, because the mean of its divisors is an integer number (411686287).

Almost surely, 2^1645611133 is an apocalyptic number.

It is an amenable number.

1645611133 is a deficient number, since it is larger than the sum of its proper divisors (1134015).

1645611133 is a wasteful number, since it uses less digits than its factorization.

1645611133 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1134014.

The product of its digits is 6480, while the sum is 31.

The square root of 1645611133 is about 40566.1328326968. The cubic root of 1645611133 is about 1180.6171082670.

Adding to 1645611133 its reverse (3311165461), we get a palindrome (4956776594).

The spelling of 1645611133 in words is "one billion, six hundred forty-five million, six hundred eleven thousand, one hundred thirty-three".