6461643861 has 56 divisors (see below), whose sum is σ = 10230480000. Its totient is φ = 4068029952.

The previous prime is 6461643827. The next prime is 6461643887. The reversal of 6461643861 is 1683461646.

It is not a de Polignac number, because 6461643861 - 2¹⁴ = 6461627477 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6461543861) by changing a digit.

It is a polite number, since it can be written in 55 ways as a sum of consecutive naturals, for example, 6218580 + ... + 6219618.

Almost surely, 2^6461643861 is an apocalyptic number.

It is an amenable number.

6461643861 is a deficient number, since it is larger than the sum of its proper divisors (3768836139).

6461643861 is a wasteful number, since it uses less digits than its factorization.

6461643861 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1525 (or 1510 counting only the distinct ones).

The product of its digits is 497664, while the sum is 45.

The square root of 6461643861 is about 80384.3508464179. The cubic root of 6461643861 is about 1862.5774438978.

The spelling of 6461643861 in words is "six billion, four hundred sixty-one million, six hundred forty-three thousand, eight hundred sixty-one".