641266261 has 4 divisors (see below), whose sum is σ = 654910272. Its totient is φ = 627622252.

The previous prime is 641266201. The next prime is 641266273. The reversal of 641266261 is 162662146.

641266261 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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.

It is a cyclic number.

It is not a de Polignac number, because 641266261 - 2²⁷ = 507048533 is a prime.

It is a super-2 number, since 2×641266261² = 822444834993840242, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (641266201) 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, 6821935 + ... + 6822028.

It is an arithmetic number, because the mean of its divisors is an integer number (163727568).

Almost surely, 2^641266261 is an apocalyptic number.

It is an amenable number.

641266261 is a deficient number, since it is larger than the sum of its proper divisors (13644011).

641266261 is a wasteful number, since it uses less digits than its factorization.

641266261 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13644010.

The product of its digits is 20736, while the sum is 34.

The square root of 641266261 is about 25323.2355950025. The cubic root of 641266261 is about 862.3418508885.

The spelling of 641266261 in words is "six hundred forty-one million, two hundred sixty-six thousand, two hundred sixty-one".