643553225 has 48 divisors (see below), whose sum is σ = 956724480. Its totient is φ = 419865600.

The previous prime is 643553221. The next prime is 643553227. The reversal of 643553225 is 522355346.

It is not a de Polignac number, because 643553225 - 2² = 643553221 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (35).

It is not an unprimeable number, because it can be changed into a prime (643553221) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1130741 + ... + 1131309.

It is an arithmetic number, because the mean of its divisors is an integer number (19931760).

Almost surely, 2^643553225 is an apocalyptic number.

It is an amenable number.

643553225 is a deficient number, since it is larger than the sum of its proper divisors (313171255).

643553225 is a wasteful number, since it uses less digits than its factorization.

643553225 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 890 (or 885 counting only the distinct ones).

The product of its digits is 108000, while the sum is 35.

The square root of 643553225 is about 25368.3508529821. The cubic root of 643553225 is about 863.3657651272.

It can be divided in two parts, 64 and 3553225, that multiplied together give a square (227406400 = 15080²).

The spelling of 643553225 in words is "six hundred forty-three million, five hundred fifty-three thousand, two hundred twenty-five".