641405791 has 4 divisors (see below), whose sum is σ = 690744712. Its totient is φ = 592066872.

The previous prime is 641405783. The next prime is 641405803. The reversal of 641405791 is 197504146.

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 641405791 - 2³ = 641405783 is a prime.

It is a super-2 number, since 2×641405791² = 822802777456671362, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 641405791.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (641405711) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 24669441 + ... + 24669466.

It is an arithmetic number, because the mean of its divisors is an integer number (172686178).

Almost surely, 2^641405791 is an apocalyptic number.

641405791 is a deficient number, since it is larger than the sum of its proper divisors (49338921).

641405791 is a wasteful number, since it uses less digits than its factorization.

641405791 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 49338920.

The product of its (nonzero) digits is 30240, while the sum is 37.

The square root of 641405791 is about 25325.9904248580. The cubic root of 641405791 is about 862.4043906062.

The spelling of 641405791 in words is "six hundred forty-one million, four hundred five thousand, seven hundred ninety-one".