6641779779 has 24 divisors (see below), whose sum is σ = 9690602064. Its totient is φ = 4383288000.

The previous prime is 6641779777. The next prime is 6641779811. The reversal of 6641779779 is 9779771466.

6641779779 is a `hidden beast` number, since 66 + 417 + 7 + 97 + 79 = 666.

It is not a de Polignac number, because 6641779779 - 2¹ = 6641779777 is a prime.

It is a super-2 number, since 2×6641779779² = 88226477265466577682, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (6641779777) 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, 489669 + ... + 503049.

It is an arithmetic number, because the mean of its divisors is an integer number (403775086).

Almost surely, 2^6641779779 is an apocalyptic number.

6641779779 is a deficient number, since it is larger than the sum of its proper divisors (3048822285).

6641779779 is a wasteful number, since it uses less digits than its factorization.

6641779779 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13939 (or 13936 counting only the distinct ones).

The product of its digits is 28005264, while the sum is 63.

The square root of 6641779779 is about 81497.1151575318. The cubic root of 6641779779 is about 1879.7271917220.

The spelling of 6641779779 in words is "six billion, six hundred forty-one million, seven hundred seventy-nine thousand, seven hundred seventy-nine".