643383225 has 81 divisors (see below), whose sum is σ = 1230032973. Its totient is φ = 321425280.

The previous prime is 643383211. The next prime is 643383229. The reversal of 643383225 is 522383346.

It is a happy number.

The square root of 643383225 is 25365.

It is a perfect power (a square), and thus also a powerful number.

643383225 is a `hidden beast` number, since 643 + 3 + 8 + 3 + 2 + 2 + 5 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 133888041 + 509495184 = 11571^2 + 22572^2 .

It is not a de Polignac number, because 643383225 - 2⁹ = 643382713 is a prime.

It is a super-2 number, since 2×643383225² = 827883948422801250, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 643383225.

It is not an unprimeable number, because it can be changed into a prime (643383229) by changing a digit.

It is a polite number, since it can be written in 80 ways as a sum of consecutive naturals, for example, 7228981 + ... + 7229069.

Almost surely, 2^643383225 is an apocalyptic number.

643383225 is the 25365-th square number.

643383225 is the 12683-rd centered octagonal number.

It is an amenable number.

643383225 is a deficient number, since it is larger than the sum of its proper divisors (586649748).

643383225 is a wasteful number, since it uses less digits than its factorization.

643383225 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 232 (or 116 counting only the distinct ones).

The product of its digits is 103680, while the sum is 36.

The cubic root of 643383225 is about 863.2897366548.

Multiplying 643383225 by its sum of digits (36), we get a square (23161796100 = 152190²).

The spelling of 643383225 in words is "six hundred forty-three million, three hundred eighty-three thousand, two hundred twenty-five".