643072501 has 4 divisors (see below), whose sum is σ = 648136192. Its totient is φ = 638008812.

The previous prime is 643072487. The next prime is 643072511. The reversal of 643072501 is 105270346.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 105270346 = 2 ⋅52635173.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-643072501 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 643072501.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (643072511) 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, 2531655 + ... + 2531908.

It is an arithmetic number, because the mean of its divisors is an integer number (162034048).

Almost surely, 2^643072501 is an apocalyptic number.

It is an amenable number.

643072501 is a deficient number, since it is larger than the sum of its proper divisors (5063691).

643072501 is a wasteful number, since it uses less digits than its factorization.

643072501 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5063690.

The product of its (nonzero) digits is 5040, while the sum is 28.

The square root of 643072501 is about 25358.8742060841. The cubic root of 643072501 is about 863.1507380899.

The spelling of 643072501 in words is "six hundred forty-three million, seventy-two thousand, five hundred one".