643574461 has 4 divisors (see below), whose sum is σ = 654124924. Its totient is φ = 633024000.

The previous prime is 643574429. The next prime is 643574471. The reversal of 643574461 is 164475346.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 86378436 + 557196025 = 9294^2 + 23605^2 .

It is a cyclic number.

It is not a de Polignac number, because 643574461 - 2⁵ = 643574429 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (643574401) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5275140 + ... + 5275261.

It is an arithmetic number, because the mean of its divisors is an integer number (163531231).

Almost surely, 2^643574461 is an apocalyptic number.

643574461 is a gapful number since it is divisible by the number (61) formed by its first and last digit.

It is an amenable number.

643574461 is a deficient number, since it is larger than the sum of its proper divisors (10550463).

643574461 is a wasteful number, since it uses less digits than its factorization.

643574461 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10550462.

The product of its digits is 241920, while the sum is 40.

The square root of 643574461 is about 25368.7694025548. The cubic root of 643574461 is about 863.3752614843.

The spelling of 643574461 in words is "six hundred forty-three million, five hundred seventy-four thousand, four hundred sixty-one".