6447491556 has 48 divisors (see below), whose sum is σ = 16496897088. Its totient is φ = 1943654400.

The previous prime is 6447491527. The next prime is 6447491579. The reversal of 6447491556 is 6551947446.

It is a happy number.

It is a super-2 number, since 2×6447491556² = 83140294729382602272, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 6447491499 and 6447491508.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 101065 + ... + 152016.

It is an arithmetic number, because the mean of its divisors is an integer number (343685356).

Almost surely, 2^6447491556 is an apocalyptic number.

6447491556 is a gapful number since it is divisible by the number (66) formed by its first and last digit.

It is an amenable number.

6447491556 is an abundant number, since it is smaller than the sum of its proper divisors (10049405532).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

6447491556 is a wasteful number, since it uses less digits than its factorization.

6447491556 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 253292 (or 253290 counting only the distinct ones).

The product of its digits is 3628800, while the sum is 51.

The square root of 6447491556 is about 80296.2736121671. The cubic root of 6447491556 is about 1861.2166430194.

The spelling of 6447491556 in words is "six billion, four hundred forty-seven million, four hundred ninety-one thousand, five hundred fifty-six".