778921650 has 96 divisors (see below), whose sum is σ = 2311518720. Its totient is φ = 191730240.

The previous prime is 778921631. The next prime is 778921679. The reversal of 778921650 is 56129877.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a junction number, because it is equal to n+sod(n) for n = 778921596 and 778921605.

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 in 47 ways as a sum of consecutive naturals, for example, 4642 + ... + 39741.

It is an arithmetic number, because the mean of its divisors is an integer number (24078320).

Almost surely, 2^778921650 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 778921650, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1155759360).

778921650 is an abundant number, since it is smaller than the sum of its proper divisors (1532597070).

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

778921650 is a wasteful number, since it uses less digits than its factorization.

778921650 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 44417 (or 44406 counting only the distinct ones).

The product of its (nonzero) digits is 211680, while the sum is 45.

The square root of 778921650 is about 27909.1678485762. The cubic root of 778921650 is about 920.0920079689.

The spelling of 778921650 in words is "seven hundred seventy-eight million, nine hundred twenty-one thousand, six hundred fifty".