19640128231 has 2 divisors, whose sum is σ = 19640128232. Its totient is φ = 19640128230.

The previous prime is 19640128223. The next prime is 19640128247. The reversal of 19640128231 is 13282104691.

It is a weak prime.

It is an emirp because it is prime and its reverse (13282104691) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 19640128231 - 2³ = 19640128223 is a prime.

It is a super-2 number, since 2×19640128231² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (19640128531) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9820064115 + 9820064116.

It is an arithmetic number, because the mean of its divisors is an integer number (9820064116).

Almost surely, 2^19640128231 is an apocalyptic number.

19640128231 is a deficient number, since it is larger than the sum of its proper divisors (1).

19640128231 is an equidigital number, since it uses as much as digits as its factorization.

19640128231 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 20736, while the sum is 37.

The spelling of 19640128231 in words is "nineteen billion, six hundred forty million, one hundred twenty-eight thousand, two hundred thirty-one".