1209920878 has 16 divisors (see below), whose sum is σ = 1823799600. Its totient is φ = 601995456.

The previous prime is 1209920863. The next prime is 1209920891. The reversal of 1209920878 is 8780299021.

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 in 7 ways as a sum of consecutive naturals, for example, 408250 + ... + 411202.

It is an arithmetic number, because the mean of its divisors is an integer number (113987475).

Almost surely, 2^1209920878 is an apocalyptic number.

1209920878 is a deficient number, since it is larger than the sum of its proper divisors (613878722).

1209920878 is a wasteful number, since it uses less digits than its factorization.

1209920878 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3891.

The product of its (nonzero) digits is 145152, while the sum is 46.

The square root of 1209920878 is about 34783.9169444731. The cubic root of 1209920878 is about 1065.5790096542.

The spelling of 1209920878 in words is "one billion, two hundred nine million, nine hundred twenty thousand, eight hundred seventy-eight".