647451840 has 448 divisors, whose sum is σ = 2528133120. Its totient is φ = 137195520.

The previous prime is 647451839. The next prime is 647451881. The reversal of 647451840 is 48154746.

It is a tau number, because it is divible by the number of its divisors (448).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 9119005 + ... + 9119075.

Almost surely, 2^647451840 is an apocalyptic number.

647451840 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 647451840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1264066560).

647451840 is an abundant number, since it is smaller than the sum of its proper divisors (1880681280).

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

647451840 is a wasteful number, since it uses less digits than its factorization.

647451840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 180 (or 170 counting only the distinct ones).

The product of its (nonzero) digits is 107520, while the sum is 39.

The square root of 647451840 is about 25445.0749655017. The cubic root of 647451840 is about 865.1056660874.

The spelling of 647451840 in words is "six hundred forty-seven million, four hundred fifty-one thousand, eight hundred forty".