345686778 has 40 divisors (see below), whose sum is σ = 784428480. Its totient is φ = 113766120.

The previous prime is 345686773. The next prime is 345686791. The reversal of 345686778 is 877686543.

345686778 is a `hidden beast` number, since 3 + 4 + 568 + 6 + 7 + 78 = 666.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is not an unprimeable number, because it can be changed into a prime (345686773) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 708 + ... + 26303.

It is an arithmetic number, because the mean of its divisors is an integer number (19610712).

Almost surely, 2^345686778 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 345686778, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (392214240).

345686778 is an abundant number, since it is smaller than the sum of its proper divisors (438741702).

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

345686778 is a wasteful number, since it uses less digits than its factorization.

345686778 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27104 (or 27095 counting only the distinct ones).

The product of its digits is 6773760, while the sum is 54.

The square root of 345686778 is about 18592.6538718925. The cubic root of 345686778 is about 701.8229884620.

The spelling of 345686778 in words is "three hundred forty-five million, six hundred eighty-six thousand, seven hundred seventy-eight".