1644135741 has 12 divisors (see below), whose sum is σ = 2399347132. Its totient is φ = 1084790016.

The previous prime is 1644135719. The next prime is 1644135769. The reversal of 1644135741 is 1475314461.

1644135741 is a `hidden beast` number, since 1 + 644 + 1 + 3 + 5 + 7 + 4 + 1 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 370716516 + 1273419225 = 19254^2 + 35685^2 .

It is not a de Polignac number, because 1644135741 - 2⁵ = 1644135709 is a prime.

It is a super-3 number, since 3×1644135741³ (a number of 29 digits) contains 333 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1644135696 and 1644135705.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1644135781) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 940786 + ... + 942531.

Almost surely, 2^1644135741 is an apocalyptic number.

It is an amenable number.

1644135741 is a deficient number, since it is larger than the sum of its proper divisors (755211391).

1644135741 is a wasteful number, since it uses less digits than its factorization.

1644135741 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1883420 (or 1883417 counting only the distinct ones).

The product of its digits is 40320, while the sum is 36.

The square root of 1644135741 is about 40547.9437333140. The cubic root of 1644135741 is about 1180.2641707217.

The spelling of 1644135741 in words is "one billion, six hundred forty-four million, one hundred thirty-five thousand, seven hundred forty-one".