19685870051 has 4 divisors (see below), whose sum is σ = 19688608752. Its totient is φ = 19683131352.

The previous prime is 19685870047. The next prime is 19685870081. The reversal of 19685870051 is 15007858691.

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 19685870051 - 2² = 19685870047 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (19685870081) 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, 1358540 + ... + 1372953.

It is an arithmetic number, because the mean of its divisors is an integer number (4922152188).

Almost surely, 2^19685870051 is an apocalyptic number.

19685870051 is a deficient number, since it is larger than the sum of its proper divisors (2738701).

19685870051 is an equidigital number, since it uses as much as digits as its factorization.

19685870051 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2738700.

The product of its (nonzero) digits is 604800, while the sum is 50.

The spelling of 19685870051 in words is "nineteen billion, six hundred eighty-five million, eight hundred seventy thousand, fifty-one".