19967557871 has 2 divisors, whose sum is σ = 19967557872. Its totient is φ = 19967557870.

The previous prime is 19967557867. The next prime is 19967557889. The reversal of 19967557871 is 17875576991.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 19967557871 - 2² = 19967557867 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 19967557798 and 19967557807.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (19967557861) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9983778935 + 9983778936.

It is an arithmetic number, because the mean of its divisors is an integer number (9983778936).

Almost surely, 2^19967557871 is an apocalyptic number.

19967557871 is a deficient number, since it is larger than the sum of its proper divisors (1).

19967557871 is an equidigital number, since it uses as much as digits as its factorization.

19967557871 is an evil number, because the sum of its binary digits is even.

The product of its digits is 33339600, while the sum is 65.

The spelling of 19967557871 in words is "nineteen billion, nine hundred sixty-seven million, five hundred fifty-seven thousand, eight hundred seventy-one".