643180920 has 32 divisors (see below), whose sum is σ = 1929543120. Its totient is φ = 171514880.

The previous prime is 643180919. The next prime is 643180927. The reversal of 643180920 is 29081346.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (643180927) 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, 2679801 + ... + 2680040.

Almost surely, 2^643180920 is an apocalyptic number.

643180920 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

643180920 is an abundant number, since it is smaller than the sum of its proper divisors (1286362200).

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

643180920 is a wasteful number, since it uses less digits than its factorization.

643180920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5359855 (or 5359851 counting only the distinct ones).

The product of its (nonzero) digits is 10368, while the sum is 33.

The square root of 643180920 is about 25361.0118094685. The cubic root of 643180920 is about 863.1992430827.

The spelling of 643180920 in words is "six hundred forty-three million, one hundred eighty thousand, nine hundred twenty".