781061328 has 60 divisors (see below), whose sum is σ = 2314475748. Its totient is φ = 245038080.

The previous prime is 781061297. The next prime is 781061339. The reversal of 781061328 is 823160187.

781061328 is a `hidden beast` number, since 7 + 8 + 10 + 613 + 28 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 405941904 + 375119424 = 20148^2 + 19368^2 .

It is a super-2 number, since 2×781061328² = 1220113596194247168, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 781061292 and 781061301.

It is a congruent number.

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 11 ways as a sum of consecutive naturals, for example, 157083 + ... + 161978.

Almost surely, 2^781061328 is an apocalyptic number.

It is an amenable number.

781061328 is an abundant number, since it is smaller than the sum of its proper divisors (1533414420).

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

781061328 is a wasteful number, since it uses less digits than its factorization.

781061328 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 319092 (or 319083 counting only the distinct ones).

The product of its (nonzero) digits is 16128, while the sum is 36.

The square root of 781061328 is about 27947.4744476133. The cubic root of 781061328 is about 920.9337275079.

The spelling of 781061328 in words is "seven hundred eighty-one million, sixty-one thousand, three hundred twenty-eight".