643636956074 has 16 divisors (see below), whose sum is σ = 1138970466816. Its totient is φ = 266946202800.

The previous prime is 643636956041. The next prime is 643636956077. The reversal of 643636956074 is 470659636346.

643636956074 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not an unprimeable number, because it can be changed into a prime (643636956077) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 741516797 + ... + 741517664.

It is an arithmetic number, because the mean of its divisors is an integer number (71185654176).

Almost surely, 2^643636956074 is an apocalyptic number.

643636956074 is a deficient number, since it is larger than the sum of its proper divisors (495333510742).

643636956074 is a wasteful number, since it uses less digits than its factorization.

643636956074 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1483034501.

The product of its (nonzero) digits is 58786560, while the sum is 59.

The spelling of 643636956074 in words is "six hundred forty-three billion, six hundred thirty-six million, nine hundred fifty-six thousand, seventy-four".