643777134 has 128 divisors (see below), whose sum is σ = 1776079872. Its totient is φ = 150128640.

The previous prime is 643777129. The next prime is 643777193. The reversal of 643777134 is 431777346.

It is a super-2 number, since 2×643777134² = 828897996522507912, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a congruent number.

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, 220774 + ... + 223670.

It is an arithmetic number, because the mean of its divisors is an integer number (13875624).

Almost surely, 2^643777134 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 643777134, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (888039936).

643777134 is an abundant number, since it is smaller than the sum of its proper divisors (1132302738).

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

643777134 is a wasteful number, since it uses less digits than its factorization.

643777134 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2970.

The product of its digits is 296352, while the sum is 42.

The square root of 643777134 is about 25372.7636255888. The cubic root of 643777134 is about 863.4658826943.

It can be divided in two parts, 643 and 777134, that added together give a palindrome (777777).

The spelling of 643777134 in words is "six hundred forty-three million, seven hundred seventy-seven thousand, one hundred thirty-four".