641916649 has 16 divisors (see below), whose sum is σ = 707730624. Its totient is φ = 577382400.

The previous prime is 641916643. The next prime is 641916677. The reversal of 641916649 is 946619146.

It is a cyclic number.

It is not a de Polignac number, because 641916649 - 2⁹ = 641916137 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 641916599 and 641916608.

It is not an unprimeable number, because it can be changed into a prime (641916643) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 447237 + ... + 448669.

It is an arithmetic number, because the mean of its divisors is an integer number (44233164).

Almost surely, 2^641916649 is an apocalyptic number.

It is an amenable number.

641916649 is a deficient number, since it is larger than the sum of its proper divisors (65813975).

641916649 is a wasteful number, since it uses less digits than its factorization.

641916649 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1848.

The product of its digits is 279936, while the sum is 46.

The square root of 641916649 is about 25336.0740644639. The cubic root of 641916649 is about 862.6332884816.

The spelling of 641916649 in words is "six hundred forty-one million, nine hundred sixteen thousand, six hundred forty-nine".