643542670 has 16 divisors (see below), whose sum is σ = 1163439360. Its totient is φ = 256292064.

The previous prime is 643542643. The next prime is 643542689. The reversal of 643542670 is 76245346.

It is a super-2 number, since 2×643542670² = 828294336221457800, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 138222 + ... + 142801.

It is an arithmetic number, because the mean of its divisors is an integer number (72714960).

Almost surely, 2^643542670 is an apocalyptic number.

643542670 is a deficient number, since it is larger than the sum of its proper divisors (519896690).

643542670 is a wasteful number, since it uses less digits than its factorization.

643542670 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 281259.

The product of its (nonzero) digits is 120960, while the sum is 37.

The square root of 643542670 is about 25368.1428173211. The cubic root of 643542670 is about 863.3610450433.

The spelling of 643542670 in words is "six hundred forty-three million, five hundred forty-two thousand, six hundred seventy".