1968635138 has 16 divisors (see below), whose sum is σ = 3060802944. Its totient is φ = 948992880.

The previous prime is 1968635117. The next prime is 1968635143. The reversal of 1968635138 is 8315368691.

It is a happy number.

It is a Curzon 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, 149993 + ... + 162588.

It is an arithmetic number, because the mean of its divisors is an integer number (191300184).

Almost surely, 2^1968635138 is an apocalyptic number.

1968635138 is a deficient number, since it is larger than the sum of its proper divisors (1092167806).

1968635138 is a wasteful number, since it uses less digits than its factorization.

1968635138 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 312697.

The product of its digits is 933120, while the sum is 50.

The square root of 1968635138 is about 44369.3040062609. The cubic root of 1968635138 is about 1253.3001091961.

The spelling of 1968635138 in words is "one billion, nine hundred sixty-eight million, six hundred thirty-five thousand, one hundred thirty-eight".