19906743867 has 4 divisors (see below), whose sum is σ = 26542325160. Its totient is φ = 13271162576.

The previous prime is 19906743841. The next prime is 19906743881. The reversal of 19906743867 is 76834760991.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 19906743867 - 2⁸ = 19906743611 is a prime.

It is a super-2 number, since 2×19906743867² (a number of 21 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 19906743867.

It is not an unprimeable number, because it can be changed into a prime (19906741867) 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, 3317790642 + ... + 3317790647.

It is an arithmetic number, because the mean of its divisors is an integer number (6635581290).

Almost surely, 2^19906743867 is an apocalyptic number.

19906743867 is a deficient number, since it is larger than the sum of its proper divisors (6635581293).

19906743867 is an equidigital number, since it uses as much as digits as its factorization.

19906743867 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6635581292.

The product of its (nonzero) digits is 13716864, while the sum is 60.

The spelling of 19906743867 in words is "nineteen billion, nine hundred six million, seven hundred forty-three thousand, eight hundred sixty-seven".