643358851 has 2 divisors, whose sum is σ = 643358852. Its totient is φ = 643358850.

The previous prime is 643358843. The next prime is 643358893. The reversal of 643358851 is 158853346.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 643358851 - 2³ = 643358843 is a prime.

It is a super-2 number, since 2×643358851² = 827821222320080402, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 643358798 and 643358807.

It is not a weakly prime, because it can be changed into another prime (643358831) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 321679425 + 321679426.

It is an arithmetic number, because the mean of its divisors is an integer number (321679426).

Almost surely, 2^643358851 is an apocalyptic number.

643358851 is a deficient number, since it is larger than the sum of its proper divisors (1).

643358851 is an equidigital number, since it uses as much as digits as its factorization.

643358851 is an evil number, because the sum of its binary digits is even.

The product of its digits is 345600, while the sum is 43.

The square root of 643358851 is about 25364.5195302415. The cubic root of 643358851 is about 863.2788348631.

The spelling of 643358851 in words is "six hundred forty-three million, three hundred fifty-eight thousand, eight hundred fifty-one".