1209678786 has 48 divisors (see below), whose sum is σ = 2742221664. Its totient is φ = 399639744.

The previous prime is 1209678779. The next prime is 1209678787. The reversal of 1209678786 is 6878769021.

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 (1209678787) by changing a digit.

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 23 ways as a sum of consecutive naturals, for example, 43905 + ... + 65931.

It is an arithmetic number, because the mean of its divisors is an integer number (57129618).

Almost surely, 2^1209678786 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1209678786, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1371110832).

1209678786 is an abundant number, since it is smaller than the sum of its proper divisors (1532542878).

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

1209678786 is a wasteful number, since it uses less digits than its factorization.

1209678786 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22157 (or 22145 counting only the distinct ones).

The product of its (nonzero) digits is 2032128, while the sum is 54.

The square root of 1209678786 is about 34780.4368287691. The cubic root of 1209678786 is about 1065.5079346592.

The spelling of 1209678786 in words is "one billion, two hundred nine million, six hundred seventy-eight thousand, seven hundred eighty-six".