643340252 has 12 divisors (see below), whose sum is σ = 1128290856. Its totient is φ = 320971440.

The previous prime is 643340251. The next prime is 643340267. The reversal of 643340252 is 252043346.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (643340251) 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, 172598 + ... + 176285.

It is an arithmetic number, because the mean of its divisors is an integer number (94024238).

Almost surely, 2^643340252 is an apocalyptic number.

It is an amenable number.

643340252 is a deficient number, since it is larger than the sum of its proper divisors (484950604).

643340252 is a wasteful number, since it uses less digits than its factorization.

643340252 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 349348 (or 349346 counting only the distinct ones).

The product of its (nonzero) digits is 17280, while the sum is 29.

The square root of 643340252 is about 25364.1528934045. The cubic root of 643340252 is about 863.2705158782.

Adding to 643340252 its reverse (252043346), we get a palindrome (895383598).

The spelling of 643340252 in words is "six hundred forty-three million, three hundred forty thousand, two hundred fifty-two".