643031136 has 240 divisors, whose sum is σ = 2173469760. Its totient is φ = 184446720.

The previous prime is 643031131. The next prime is 643031149. The reversal of 643031136 is 631130346.

643031136 is a `hidden beast` number, since 643 + 0 + 3 + 1 + 13 + 6 = 666.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (643031131) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 541135 + ... + 542321.

It is an arithmetic number, because the mean of its divisors is an integer number (9056124).

Almost surely, 2^643031136 is an apocalyptic number.

643031136 is a gapful number since it is divisible by the number (66) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 643031136, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1086734880).

643031136 is an abundant number, since it is smaller than the sum of its proper divisors (1530438624).

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

643031136 is a wasteful number, since it uses less digits than its factorization.

643031136 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1239 (or 1222 counting only the distinct ones).

The product of its (nonzero) digits is 3888, while the sum is 27.

The square root of 643031136 is about 25358.0586007683. The cubic root of 643031136 is about 863.1322305884.

The spelling of 643031136 in words is "six hundred forty-three million, thirty-one thousand, one hundred thirty-six".