643550013 has 6 divisors (see below), whose sum is σ = 929572254. Its totient is φ = 429033336.

The previous prime is 643549999. The next prime is 643550027. The reversal of 643550013 is 310055346.

643550013 is a `hidden beast` number, since 643 + 5 + 5 + 0 + 0 + 13 = 666.

It is an interprime number because it is at equal distance from previous prime (643549999) and next prime (643550027).

It can be written as a sum of positive squares in only one way, i.e., 604274724 + 39275289 = 24582^2 + 6267^2 .

It is not a de Polignac number, because 643550013 - 2¹⁶ = 643484477 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (643550093) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 35752770 + ... + 35752787.

It is an arithmetic number, because the mean of its divisors is an integer number (154928709).

Almost surely, 2^643550013 is an apocalyptic number.

It is an amenable number.

643550013 is a deficient number, since it is larger than the sum of its proper divisors (286022241).

643550013 is a wasteful number, since it uses less digits than its factorization.

643550013 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 71505563 (or 71505560 counting only the distinct ones).

The product of its (nonzero) digits is 5400, while the sum is 27.

The square root of 643550013 is about 25368.2875456740. The cubic root of 643550013 is about 863.3643287604.

The spelling of 643550013 in words is "six hundred forty-three million, five hundred fifty thousand, thirteen".