1978028165 has 16 divisors (see below), whose sum is σ = 2430476928. Its totient is φ = 1544577216.

The previous prime is 1978028161. The next prime is 1978028167. The reversal of 1978028165 is 5618208791.

It is a cyclic number.

It is not a de Polignac number, because 1978028165 - 2² = 1978028161 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1978028161) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 519047 + ... + 522843.

It is an arithmetic number, because the mean of its divisors is an integer number (151904808).

Almost surely, 2^1978028165 is an apocalyptic number.

It is an amenable number.

1978028165 is a deficient number, since it is larger than the sum of its proper divisors (452448763).

1978028165 is a wasteful number, since it uses less digits than its factorization.

1978028165 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6268.

The product of its (nonzero) digits is 241920, while the sum is 47.

The square root of 1978028165 is about 44475.0285553590. The cubic root of 1978028165 is about 1255.2902541830.

The spelling of 1978028165 in words is "one billion, nine hundred seventy-eight million, twenty-eight thousand, one hundred sixty-five".