643155140 has 24 divisors (see below), whose sum is σ = 1394195712. Its totient is φ = 248963040.

The previous prime is 643155137. The next prime is 643155143. The reversal of 643155140 is 41551346.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (643155137) and next prime (643155143).

It is not an unprimeable number, because it can be changed into a prime (643155143) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 518054 + ... + 519293.

It is an arithmetic number, because the mean of its divisors is an integer number (58091488).

Almost surely, 2^643155140 is an apocalyptic number.

It is an amenable number.

643155140 is an abundant number, since it is smaller than the sum of its proper divisors (751040572).

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

643155140 is a wasteful number, since it uses less digits than its factorization.

643155140 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1037387 (or 1037385 counting only the distinct ones).

The product of its (nonzero) digits is 7200, while the sum is 29.

The square root of 643155140 is about 25360.5035438968. The cubic root of 643155140 is about 863.1877100013.

The spelling of 643155140 in words is "six hundred forty-three million, one hundred fifty-five thousand, one hundred forty".