641961 has 6 divisors (see below), whose sum is σ = 927290. Its totient is φ = 427968.

The previous prime is 641959. The next prime is 641969. The reversal of 641961 is 169146.

It can be written as a sum of positive squares in only one way, i.e., 360000 + 281961 = 600^2 + 531^2 .

It is not a de Polignac number, because 641961 - 2¹ = 641959 is a prime.

It is a super-2 number, since 2×641961² = 824227851042, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (641969) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 35656 + ... + 35673.

2⁶⁴¹⁹⁶¹ is an apocalyptic number.

It is an amenable number.

641961 is a deficient number, since it is larger than the sum of its proper divisors (285329).

641961 is a wasteful number, since it uses less digits than its factorization.

641961 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 71335 (or 71332 counting only the distinct ones).

The product of its digits is 1296, while the sum is 27.

The square root of 641961 is about 801.2246875877. The cubic root of 641961 is about 86.2653154907.

It can be divided in two parts, 64 and 1961, that added together give a square (2025 = 45²).

The spelling of 641961 in words is "six hundred forty-one thousand, nine hundred sixty-one".