19129999991 has 2 divisors, whose sum is σ = 19129999992. Its totient is φ = 19129999990.

The previous prime is 19129999981. The next prime is 19130000009. The reversal of 19129999991 is 19999992191.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 19129999991 - 2³⁴ = 1950130807 is a prime.

It is a Sophie Germain prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (19129999981) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9564999995 + 9564999996.

It is an arithmetic number, because the mean of its divisors is an integer number (9564999996).

Almost surely, 2^19129999991 is an apocalyptic number.

19129999991 is a deficient number, since it is larger than the sum of its proper divisors (1).

19129999991 is an equidigital number, since it uses as much as digits as its factorization.

19129999991 is an evil number, because the sum of its binary digits is even.

The product of its digits is 9565938, while the sum is 68.

The spelling of 19129999991 in words is "nineteen billion, one hundred twenty-nine million, nine hundred ninety-nine thousand, nine hundred ninety-one".