19945988457 has 4 divisors (see below), whose sum is σ = 26594651280. Its totient is φ = 13297325636.

The previous prime is 19945988441. The next prime is 19945988467. The reversal of 19945988457 is 75488954991.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 19945988457 - 2⁴ = 19945988441 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 19945988391 and 19945988400.

It is not an unprimeable number, because it can be changed into a prime (19945988407) 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, 3324331407 + ... + 3324331412.

It is an arithmetic number, because the mean of its divisors is an integer number (6648662820).

Almost surely, 2^19945988457 is an apocalyptic number.

It is an amenable number.

19945988457 is a deficient number, since it is larger than the sum of its proper divisors (6648662823).

19945988457 is an equidigital number, since it uses as much as digits as its factorization.

19945988457 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6648662822.

The product of its digits is 130636800, while the sum is 69.

The spelling of 19945988457 in words is "nineteen billion, nine hundred forty-five million, nine hundred eighty-eight thousand, four hundred fifty-seven".