855564783978 has 32 divisors (see below), whose sum is σ = 1811868614784. Its totient is φ = 268399982592.

The previous prime is 855564783971. The next prime is 855564783991. The reversal of 855564783978 is 879387465558.

It is not an unprimeable number, because it can be changed into a prime (855564783971) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2142426 + ... + 2510202.

It is an arithmetic number, because the mean of its divisors is an integer number (56620894212).

Almost surely, 2^855564783978 is an apocalyptic number.

855564783978 is an abundant number, since it is smaller than the sum of its proper divisors (956303830806).

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

855564783978 is a wasteful number, since it uses less digits than its factorization.

855564783978 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 390606.

The product of its digits is 2032128000, while the sum is 75.

The spelling of 855564783978 in words is "eight hundred fifty-five billion, five hundred sixty-four million, seven hundred eighty-three thousand, nine hundred seventy-eight".