643572225 has 36 divisors (see below), whose sum is σ = 1156171536. Its totient is φ = 342207840.

The previous prime is 643572197. The next prime is 643572229. The reversal of 643572225 is 522275346.

643572225 is a `hidden beast` number, since 64 + 3 + 572 + 2 + 25 = 666.

It is not a de Polignac number, because 643572225 - 2⁹ = 643571713 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 643572225.

It is not an unprimeable number, because it can be changed into a prime (643572229) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 73954 + ... + 82196.

It is an arithmetic number, because the mean of its divisors is an integer number (32115876).

Almost surely, 2^643572225 is an apocalyptic number.

It is an amenable number.

643572225 is a deficient number, since it is larger than the sum of its proper divisors (512599311).

643572225 is a wasteful number, since it uses less digits than its factorization.

643572225 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8606 (or 8598 counting only the distinct ones).

The product of its digits is 100800, while the sum is 36.

The square root of 643572225 is about 25368.7253325822. The cubic root of 643572225 is about 863.3742615951.

The spelling of 643572225 in words is "six hundred forty-three million, five hundred seventy-two thousand, two hundred twenty-five".