19316996921 has 4 divisors (see below), whose sum is σ = 19329988992. Its totient is φ = 19304004852.

The previous prime is 19316996899. The next prime is 19316996953. The reversal of 19316996921 is 12969961391.

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: 12969961391 = 87991 ⋅147401.

It is a cyclic number.

It is not a de Polignac number, because 19316996921 - 2⁶ = 19316996857 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (19316996221) 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, 6493805 + ... + 6496778.

It is an arithmetic number, because the mean of its divisors is an integer number (4832497248).

Almost surely, 2^19316996921 is an apocalyptic number.

It is an amenable number.

19316996921 is a deficient number, since it is larger than the sum of its proper divisors (12992071).

19316996921 is a wasteful number, since it uses less digits than its factorization.

19316996921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12992070.

The product of its digits is 1417176, while the sum is 56.

The spelling of 19316996921 in words is "nineteen billion, three hundred sixteen million, nine hundred ninety-six thousand, nine hundred twenty-one".