641964751 has 4 divisors (see below), whose sum is σ = 642547872. Its totient is φ = 641381632.

The previous prime is 641964749. The next prime is 641964769. The reversal of 641964751 is 157469146.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 641964751 - 2¹ = 641964749 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 641964698 and 641964707.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (641964731) 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, 289906 + ... + 292111.

It is an arithmetic number, because the mean of its divisors is an integer number (160636968).

Almost surely, 2^641964751 is an apocalyptic number.

641964751 is a deficient number, since it is larger than the sum of its proper divisors (583121).

641964751 is a wasteful number, since it uses less digits than its factorization.

641964751 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 583120.

The product of its digits is 181440, while the sum is 43.

The square root of 641964751 is about 25337.0233255606. The cubic root of 641964751 is about 862.6548350745.

The spelling of 641964751 in words is "six hundred forty-one million, nine hundred sixty-four thousand, seven hundred fifty-one".