643764353507 has 16 divisors (see below), whose sum is σ = 705706737120. Its totient is φ = 582397132800.

The previous prime is 643764353459. The next prime is 643764353513. The reversal of 643764353507 is 705353467346.

It is a cyclic number.

It is not a de Polignac number, because 643764353507 - 2³² = 639469386211 is a prime.

It is not an unprimeable number, because it can be changed into a prime (643764353537) 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, 2241563 + ... + 2512395.

It is an arithmetic number, because the mean of its divisors is an integer number (44106671070).

Almost surely, 2^643764353507 is an apocalyptic number.

643764353507 is a deficient number, since it is larger than the sum of its proper divisors (61942383613).

643764353507 is a wasteful number, since it uses less digits than its factorization.

643764353507 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 271894.

The product of its (nonzero) digits is 19051200, while the sum is 53.

The spelling of 643764353507 in words is "six hundred forty-three billion, seven hundred sixty-four million, three hundred fifty-three thousand, five hundred seven".