643475533 has 2 divisors, whose sum is σ = 643475534. Its totient is φ = 643475532.

The previous prime is 643475471. The next prime is 643475563. The reversal of 643475533 is 335574346.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 555922084 + 87553449 = 23578^2 + 9357^2 .

It is a cyclic number.

It is not a de Polignac number, because 643475533 - 2¹⁷ = 643344461 is a prime.

It is a super-3 number, since 3×643475533³ (a number of 27 digits) contains 333 as substring.

It is equal to p_33471787 and since 643475533 and 33471787 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (643475563) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 321737766 + 321737767.

It is an arithmetic number, because the mean of its divisors is an integer number (321737767).

Almost surely, 2^643475533 is an apocalyptic number.

It is an amenable number.

643475533 is a deficient number, since it is larger than the sum of its proper divisors (1).

643475533 is an equidigital number, since it uses as much as digits as its factorization.

643475533 is an evil number, because the sum of its binary digits is even.

The product of its digits is 453600, while the sum is 40.

The square root of 643475533 is about 25366.8195286678. The cubic root of 643475533 is about 863.3310208823.

The spelling of 643475533 in words is "six hundred forty-three million, four hundred seventy-five thousand, five hundred thirty-three".