781320016 has 10 divisors (see below), whose sum is σ = 1513807562. Its totient is φ = 390660000.

The previous prime is 781319989. The next prime is 781320037. The reversal of 781320016 is 610023187.

It can be written as a sum of positive squares in only one way, i.e., 762864400 + 18455616 = 27620^2 + 4296^2 .

It is a super-2 number, since 2×781320016² = 1220921934804480512, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 24416235 + ... + 24416266.

Almost surely, 2^781320016 is an apocalyptic number.

It is an amenable number.

781320016 is a deficient number, since it is larger than the sum of its proper divisors (732487546).

781320016 is a wasteful number, since it uses less digits than its factorization.

781320016 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 48832509 (or 48832503 counting only the distinct ones).

The product of its (nonzero) digits is 2016, while the sum is 28.

The square root of 781320016 is about 27952.1021749707. The cubic root of 781320016 is about 921.0353875608.

The spelling of 781320016 in words is "seven hundred eighty-one million, three hundred twenty thousand, sixteen".