781861248 has 432 divisors, whose sum is σ = 2860778700. Its totient is φ = 211631616.

The previous prime is 781861243. The next prime is 781861277. The reversal of 781861248 is 842168187.

It is a tau number, because it is divible by the number of its divisors (432).

It is a super-2 number, since 2×781861248² = 1222614022248235008, which contains 22 as substring.

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (781861243) by changing a digit.

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 53 ways as a sum of consecutive naturals, for example, 41150583 + ... + 41150601.

Almost surely, 2^781861248 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 781861248, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1430389350).

781861248 is an abundant number, since it is smaller than the sum of its proper divisors (2078917452).

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

781861248 is an frugal number, since it uses more digits than its factorization.

781861248 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 71 (or 31 counting only the distinct ones).

The product of its digits is 172032, while the sum is 45.

The square root of 781861248 is about 27961.7819174673. The cubic root of 781861248 is about 921.2480101116.

The spelling of 781861248 in words is "seven hundred eighty-one million, eight hundred sixty-one thousand, two hundred forty-eight".