641262641 has 4 divisors (see below), whose sum is σ = 641884452. Its totient is φ = 640640832.

The previous prime is 641262637. The next prime is 641262647. The reversal of 641262641 is 146262146.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 146262146 = 2 ⋅73131073.

It can be written as a sum of positive squares in 2 ways, for example, as 609102400 + 32160241 = 24680^2 + 5671^2 .

It is a cyclic number.

It is not a de Polignac number, because 641262641 - 2² = 641262637 is a prime.

It is a super-2 number, since 2×641262641² = 822435549484589762, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 641262598 and 641262607.

It is not an unprimeable number, because it can be changed into a prime (641262647) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 309356 + ... + 311421.

It is an arithmetic number, because the mean of its divisors is an integer number (160471113).

Almost surely, 2^641262641 is an apocalyptic number.

It is an amenable number.

641262641 is a deficient number, since it is larger than the sum of its proper divisors (621811).

641262641 is a wasteful number, since it uses less digits than its factorization.

641262641 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 621810.

The product of its digits is 13824, while the sum is 32.

The square root of 641262641 is about 25323.1641190433. The cubic root of 641262641 is about 862.3402282223.

The spelling of 641262641 in words is "six hundred forty-one million, two hundred sixty-two thousand, six hundred forty-one".