1978851009 has 16 divisors (see below), whose sum is σ = 2672784000. Its totient is φ = 1302128256.

The previous prime is 1978851001. The next prime is 1978851029. The reversal of 1978851009 is 9001588791.

It is not a de Polignac number, because 1978851009 - 2³ = 1978851001 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1978851001) 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, 153747 + ... + 166119.

It is an arithmetic number, because the mean of its divisors is an integer number (167049000).

Almost surely, 2^1978851009 is an apocalyptic number.

It is an amenable number.

1978851009 is a deficient number, since it is larger than the sum of its proper divisors (693932991).

1978851009 is a wasteful number, since it uses less digits than its factorization.

1978851009 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13064.

The product of its (nonzero) digits is 181440, while the sum is 48.

The square root of 1978851009 is about 44484.2782227609. The cubic root of 1978851009 is about 1255.4642936428.

The spelling of 1978851009 in words is "one billion, nine hundred seventy-eight million, eight hundred fifty-one thousand, nine".