643122792 has 288 divisors, whose sum is σ = 2092490400. Its totient is φ = 176795136.

The previous prime is 643122787. The next prime is 643122839. The reversal of 643122792 is 297221346.

643122792 is a `hidden beast` number, since 643 + 1 + 2 + 2 + 7 + 9 + 2 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

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 71 ways as a sum of consecutive naturals, for example, 14956323 + ... + 14956365.

Almost surely, 2^643122792 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 643122792, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1046245200).

643122792 is an abundant number, since it is smaller than the sum of its proper divisors (1449367608).

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

643122792 is a wasteful number, since it uses less digits than its factorization.

643122792 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 145 (or 109 counting only the distinct ones).

The product of its digits is 36288, while the sum is 36.

The square root of 643122792 is about 25359.8657725154. The cubic root of 643122792 is about 863.1732381875.

The spelling of 643122792 in words is "six hundred forty-three million, one hundred twenty-two thousand, seven hundred ninety-two".