643257413 has 4 divisors (see below), whose sum is σ = 648322560. Its totient is φ = 638192268.

The previous prime is 643257401. The next prime is 643257437. The reversal of 643257413 is 314752346.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 643257413 - 2⁴ = 643257397 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (643257473) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2532383 + ... + 2532636.

It is an arithmetic number, because the mean of its divisors is an integer number (162080640).

Almost surely, 2^643257413 is an apocalyptic number.

It is an amenable number.

643257413 is a deficient number, since it is larger than the sum of its proper divisors (5065147).

643257413 is a wasteful number, since it uses less digits than its factorization.

643257413 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5065146.

The product of its digits is 60480, while the sum is 35.

The square root of 643257413 is about 25362.5198472076. The cubic root of 643257413 is about 863.2334615948.

The spelling of 643257413 in words is "six hundred forty-three million, two hundred fifty-seven thousand, four hundred thirteen".