19857403541 has 2 divisors, whose sum is σ = 19857403542. Its totient is φ = 19857403540.

The previous prime is 19857403513. The next prime is 19857403561. The reversal of 19857403541 is 14530475891.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19681284100 + 176119441 = 140290^2 + 13271^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-19857403541 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (19857403561) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9928701770 + 9928701771.

It is an arithmetic number, because the mean of its divisors is an integer number (9928701771).

Almost surely, 2^19857403541 is an apocalyptic number.

It is an amenable number.

19857403541 is a deficient number, since it is larger than the sum of its proper divisors (1).

19857403541 is an equidigital number, since it uses as much as digits as its factorization.

19857403541 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 604800, while the sum is 47.

The spelling of 19857403541 in words is "nineteen billion, eight hundred fifty-seven million, four hundred three thousand, five hundred forty-one".