643111434 has 128 divisors (see below), whose sum is σ = 1702010880. Its totient is φ = 176185152.

The previous prime is 643111423. The next prime is 643111451. The reversal of 643111434 is 434111346.

643111434 is a `hidden beast` number, since 643 + 1 + 1 + 14 + 3 + 4 = 666.

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

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 643111398 and 643111407.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 941257 + ... + 941939.

It is an arithmetic number, because the mean of its divisors is an integer number (13296960).

Almost surely, 2^643111434 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 643111434, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (851005440).

643111434 is an abundant number, since it is smaller than the sum of its proper divisors (1058899446).

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

643111434 is a wasteful number, since it uses less digits than its factorization.

643111434 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 801 (or 795 counting only the distinct ones).

The product of its digits is 3456, while the sum is 27.

The square root of 643111434 is about 25359.6418350102. The cubic root of 643111434 is about 863.1681567425.

It can be divided in two parts, 643111 and 434, that added together give a triangular number (643545 = T₁₁₃₄).

The spelling of 643111434 in words is "six hundred forty-three million, one hundred eleven thousand, four hundred thirty-four".