781227648 has 96 divisors (see below), whose sum is σ = 2257316100. Its totient is φ = 259338240.

The previous prime is 781227613. The next prime is 781227659. The reversal of 781227648 is 846722187.

It can be written as a sum of positive squares in 2 ways, for example, as 501401664 + 279825984 = 22392^2 + 16728^2 .

It is a tau number, because it is divible by the number of its divisors (96).

It is a super-2 number, since 2×781227648² = 1220633275999223808, which contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 308628 + ... + 311148.

Almost surely, 2^781227648 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 781227648, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1128658050).

781227648 is an abundant number, since it is smaller than the sum of its proper divisors (1476088452).

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

781227648 is a wasteful number, since it uses less digits than its factorization.

781227648 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2810 (or 2795 counting only the distinct ones).

The product of its digits is 301056, while the sum is 45.

The square root of 781227648 is about 27950.4498711559. The cubic root of 781227648 is about 920.9990910593. Note that the first 3 decimals are identical.

It can be divided in two parts, 781227 and 648, that added together give a triangular number (781875 = T₁₂₅₀).

The spelling of 781227648 in words is "seven hundred eighty-one million, two hundred twenty-seven thousand, six hundred forty-eight".