6447561249 has 4 divisors (see below), whose sum is σ = 8596748336. Its totient is φ = 4298374164.

The previous prime is 6447561223. The next prime is 6447561299. The reversal of 6447561249 is 9421657446.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 6447561249 - 2⁷ = 6447561121 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 6447561198 and 6447561207.

It is not an unprimeable number, because it can be changed into a prime (6447561299) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1074593539 + ... + 1074593544.

It is an arithmetic number, because the mean of its divisors is an integer number (2149187084).

Almost surely, 2^6447561249 is an apocalyptic number.

It is an amenable number.

6447561249 is a deficient number, since it is larger than the sum of its proper divisors (2149187087).

6447561249 is a wasteful number, since it uses less digits than its factorization.

6447561249 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2149187086.

The product of its digits is 1451520, while the sum is 48.

The square root of 6447561249 is about 80296.7075850561. The cubic root of 6447561249 is about 1861.2233491574.

The spelling of 6447561249 in words is "six billion, four hundred forty-seven million, five hundred sixty-one thousand, two hundred forty-nine".