641183781 has 24 divisors (see below), whose sum is σ = 1037905600. Its totient is φ = 344835072.

The previous prime is 641183779. The next prime is 641183783. The reversal of 641183781 is 187381146.

It is an interprime number because it is at equal distance from previous prime (641183779) and next prime (641183783).

It is not a de Polignac number, because 641183781 - 2¹ = 641183779 is a prime.

It is a super-2 number, since 2×641183781² = 822233282034911922, 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 (641183783) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 46756 + ... + 58893.

Almost surely, 2^641183781 is an apocalyptic number.

It is an amenable number.

641183781 is a deficient number, since it is larger than the sum of its proper divisors (396721819).

641183781 is a wasteful number, since it uses less digits than its factorization.

641183781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 105693 (or 105676 counting only the distinct ones).

The product of its digits is 32256, while the sum is 39.

The square root of 641183781 is about 25321.6069987669. The cubic root of 641183781 is about 862.3048776842.

The spelling of 641183781 in words is "six hundred forty-one million, one hundred eighty-three thousand, seven hundred eighty-one".