1978165636 has 12 divisors (see below), whose sum is σ = 3542296912. Its totient is φ = 966080808.

The previous prime is 1978165633. The next prime is 1978165649. The reversal of 1978165636 is 6365618791.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (1978165633) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5750310 + ... + 5750653.

Almost surely, 2^1978165636 is an apocalyptic number.

It is an amenable number.

1978165636 is a deficient number, since it is larger than the sum of its proper divisors (1564131276).

1978165636 is a wasteful number, since it uses less digits than its factorization.

1978165636 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11501010 (or 11501008 counting only the distinct ones).

The product of its digits is 1632960, while the sum is 52.

The square root of 1978165636 is about 44476.5740137435. The cubic root of 1978165636 is about 1255.3193339861.

The spelling of 1978165636 in words is "one billion, nine hundred seventy-eight million, one hundred sixty-five thousand, six hundred thirty-six".