1643140264 has 8 divisors (see below), whose sum is σ = 3080888010. Its totient is φ = 821570128.

The previous prime is 1643140259. The next prime is 1643140271. The reversal of 1643140264 is 4620413461.

It can be written as a sum of positive squares in only one way, i.e., 1324232100 + 318908164 = 36390^2 + 17858^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is an unprimeable number.

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 as a sum of consecutive naturals, namely, 102696259 + ... + 102696274.

Almost surely, 2^1643140264 is an apocalyptic number.

It is an amenable number.

1643140264 is a deficient number, since it is larger than the sum of its proper divisors (1437747746).

1643140264 is a wasteful number, since it uses less digits than its factorization.

1643140264 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 205392539 (or 205392535 counting only the distinct ones).

The product of its (nonzero) digits is 13824, while the sum is 31.

The square root of 1643140264 is about 40535.6665666176. Note that the first 3 decimals coincide. The cubic root of 1643140264 is about 1180.0259172705.

The spelling of 1643140264 in words is "one billion, six hundred forty-three million, one hundred forty thousand, two hundred sixty-four".