19138408651 has 4 divisors (see below), whose sum is σ = 19755776704. Its totient is φ = 18521040600.

The previous prime is 19138408643. The next prime is 19138408657. The reversal of 19138408651 is 15680483191.

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 19138408651 - 2³ = 19138408643 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (19138408657) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 308683980 + ... + 308684041.

It is an arithmetic number, because the mean of its divisors is an integer number (4938944176).

Almost surely, 2^19138408651 is an apocalyptic number.

19138408651 is a deficient number, since it is larger than the sum of its proper divisors (617368053).

19138408651 is an equidigital number, since it uses as much as digits as its factorization.

19138408651 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 617368052.

The product of its (nonzero) digits is 207360, while the sum is 46.

The spelling of 19138408651 in words is "nineteen billion, one hundred thirty-eight million, four hundred eight thousand, six hundred fifty-one".