643212245 has 8 divisors (see below), whose sum is σ = 831228216. Its totient is φ = 474987456.

The previous prime is 643212197. The next prime is 643212247. The reversal of 643212245 is 542212346.

It can be written as a sum of positive squares in 4 ways, for example, as 132181009 + 511031236 = 11497^2 + 22606^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 643212245 - 2¹⁰ = 643211221 is a prime.

It is a super-3 number, since 3×643212245³ (a number of 27 digits) contains 333 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (643212247) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4947722 + ... + 4947851.

It is an arithmetic number, because the mean of its divisors is an integer number (103903527).

Almost surely, 2^643212245 is an apocalyptic number.

643212245 is a gapful number since it is divisible by the number (65) formed by its first and last digit.

It is an amenable number.

643212245 is a deficient number, since it is larger than the sum of its proper divisors (188015971).

643212245 is a wasteful number, since it uses less digits than its factorization.

643212245 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9895591.

The product of its digits is 11520, while the sum is 29.

The square root of 643212245 is about 25361.6293837758. The cubic root of 643212245 is about 863.2132563909.

It can be divided in two parts, 64321 and 2245, that added together give a palindrome (66566).

The spelling of 643212245 in words is "six hundred forty-three million, two hundred twelve thousand, two hundred forty-five".