643506654 has 32 divisors (see below), whose sum is σ = 1491595776. Its totient is φ = 181268640.

The previous prime is 643506641. The next prime is 643506683. The reversal of 643506654 is 456605346.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 104917 + ... + 110880.

It is an arithmetic number, because the mean of its divisors is an integer number (46612368).

Almost surely, 2^643506654 is an apocalyptic number.

643506654 is an abundant number, since it is smaller than the sum of its proper divisors (848089122).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

643506654 is a wasteful number, since it uses less digits than its factorization.

643506654 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 215880.

The product of its (nonzero) digits is 259200, while the sum is 39.

The square root of 643506654 is about 25367.4329406820. The cubic root of 643506654 is about 863.3449386824.

The spelling of 643506654 in words is "six hundred forty-three million, five hundred six thousand, six hundred fifty-four".