19971019 has 2 divisors, whose sum is σ = 19971020. Its totient is φ = 19971018.

The previous prime is 19971013. The next prime is 19971023. The reversal of 19971019 is 91017991.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 19971019 - 2⁵ = 19970987 is a prime.

It is a super-2 number, since 2×19971019² = 797683199796722, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (19971013) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9985509 + 9985510.

It is an arithmetic number, because the mean of its divisors is an integer number (9985510).

Almost surely, 2^19971019 is an apocalyptic number.

19971019 is a deficient number, since it is larger than the sum of its proper divisors (1).

19971019 is an equidigital number, since it uses as much as digits as its factorization.

19971019 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5103, while the sum is 37.

The square root of 19971019 is about 4468.8946060519. The cubic root of 19971019 is about 271.3105873848.

The spelling of 19971019 in words is "nineteen million, nine hundred seventy-one thousand, nineteen".