1968390637 has 4 divisors (see below), whose sum is σ = 1970176320. Its totient is φ = 1966604956.

The previous prime is 1968390629. The next prime is 1968390659. The reversal of 1968390637 is 7360938691.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 7360938691 = 13451 ⋅547241.

It is a cyclic number.

It is not a de Polignac number, because 1968390637 - 2³ = 1968390629 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 (1968390617) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 891187 + ... + 893392.

It is an arithmetic number, because the mean of its divisors is an integer number (492544080).

Almost surely, 2^1968390637 is an apocalyptic number.

It is an amenable number.

1968390637 is a deficient number, since it is larger than the sum of its proper divisors (1785683).

1968390637 is a wasteful number, since it uses less digits than its factorization.

1968390637 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1785682.

The product of its (nonzero) digits is 1469664, while the sum is 52.

The square root of 1968390637 is about 44366.5486261891. The cubic root of 1968390637 is about 1253.2482211628.

The spelling of 1968390637 in words is "one billion, nine hundred sixty-eight million, three hundred ninety thousand, six hundred thirty-seven".