643827434057 has 16 divisors (see below), whose sum is σ = 668790794880. Its totient is φ = 619264914048.

The previous prime is 643827434011. The next prime is 643827434093. The reversal of 643827434057 is 750434728346.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 643827434057 - 2⁸ = 643827433801 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (643823434057) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 19501118 + ... + 19534104.

It is an arithmetic number, because the mean of its divisors is an integer number (41799424680).

Almost surely, 2^643827434057 is an apocalyptic number.

It is an amenable number.

643827434057 is a deficient number, since it is larger than the sum of its proper divisors (24963360823).

643827434057 is a wasteful number, since it uses less digits than its factorization.

643827434057 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 39040.

The product of its (nonzero) digits is 13547520, while the sum is 53.

The spelling of 643827434057 in words is "six hundred forty-three billion, eight hundred twenty-seven million, four hundred thirty-four thousand, fifty-seven".