19968578077 has 4 divisors (see below), whose sum is σ = 22821232096. Its totient is φ = 17115924060.

The previous prime is 19968578057. The next prime is 19968578083. The reversal of 19968578077 is 77087586991.

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.

It is a cyclic number.

It is not a de Polignac number, because 19968578077 - 2¹⁹ = 19968053789 is a prime.

It is a super-2 number, since 2×19968578077² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19968578027) 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, 1426326999 + ... + 1426327012.

It is an arithmetic number, because the mean of its divisors is an integer number (5705308024).

Almost surely, 2^19968578077 is an apocalyptic number.

It is an amenable number.

19968578077 is a deficient number, since it is larger than the sum of its proper divisors (2852654019).

19968578077 is an equidigital number, since it uses as much as digits as its factorization.

19968578077 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2852654018.

The product of its (nonzero) digits is 53343360, while the sum is 67.

The spelling of 19968578077 in words is "nineteen billion, nine hundred sixty-eight million, five hundred seventy-eight thousand, seventy-seven".