641981033 has 4 divisors (see below), whose sum is σ = 664118340. Its totient is φ = 619843728.

The previous prime is 641981009. The next prime is 641981059. The reversal of 641981033 is 330189146.

641981033 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.

It can be written as a sum of positive squares in 2 ways, for example, as 307932304 + 334048729 = 17548^2 + 18277^2 .

It is a cyclic number.

It is not a de Polignac number, because 641981033 - 2²⁸ = 373545577 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 641980984 and 641981002.

It is not an unprimeable number, because it can be changed into a prime (641981003) 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, 11068610 + ... + 11068667.

It is an arithmetic number, because the mean of its divisors is an integer number (166029585).

Almost surely, 2^641981033 is an apocalyptic number.

It is an amenable number.

641981033 is a deficient number, since it is larger than the sum of its proper divisors (22137307).

641981033 is a wasteful number, since it uses less digits than its factorization.

641981033 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22137306.

The product of its (nonzero) digits is 15552, while the sum is 35.

The square root of 641981033 is about 25337.3446319854. The cubic root of 641981033 is about 862.6621281163.

The spelling of 641981033 in words is "six hundred forty-one million, nine hundred eighty-one thousand, thirty-three".