643513901 has 8 divisors (see below), whose sum is σ = 662122944. Its totient is φ = 625043680.

The previous prime is 643513889. The next prime is 643513921. The reversal of 643513901 is 109315346.

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 643513901 - 2¹⁸ = 643251757 is a prime.

It is a super-2 number, since 2×643513901² = 828220281560475602, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (643513921) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 25265 + ... + 43878.

It is an arithmetic number, because the mean of its divisors is an integer number (82765368).

Almost surely, 2^643513901 is an apocalyptic number.

It is an amenable number.

643513901 is a deficient number, since it is larger than the sum of its proper divisors (18609043).

643513901 is a wasteful number, since it uses less digits than its factorization.

643513901 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 69411.

The product of its (nonzero) digits is 9720, while the sum is 32.

The square root of 643513901 is about 25367.5757809058. The cubic root of 643513901 is about 863.3481795903.

The spelling of 643513901 in words is "six hundred forty-three million, five hundred thirteen thousand, nine hundred one".