19998000051 has 4 divisors (see below), whose sum is σ = 26664000072. Its totient is φ = 13332000032.

The previous prime is 19998000047. The next prime is 19998000073. The reversal of 19998000051 is 15000089991.

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 19998000051 - 2² = 19998000047 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 19997999967 and 19998000012.

It is not an unprimeable number, because it can be changed into a prime (19998000091) 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, 3333000006 + ... + 3333000011.

It is an arithmetic number, because the mean of its divisors is an integer number (6666000018).

Almost surely, 2^19998000051 is an apocalyptic number.

19998000051 is a deficient number, since it is larger than the sum of its proper divisors (6666000021).

19998000051 is an equidigital number, since it uses as much as digits as its factorization.

19998000051 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6666000020.

The product of its (nonzero) digits is 29160, while the sum is 42.

The spelling of 19998000051 in words is "nineteen billion, nine hundred ninety-eight million, fifty-one", and thus it is an aban number.