19918967 has 2 divisors, whose sum is σ = 19918968. Its totient is φ = 19918966.

The previous prime is 19918963. The next prime is 19918993. The reversal of 19918967 is 76981991.

It is a weak prime.

It is an emirp because it is prime and its reverse (76981991) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 19918967 - 2² = 19918963 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (19918963) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9959483 + 9959484.

It is an arithmetic number, because the mean of its divisors is an integer number (9959484).

Almost surely, 2^19918967 is an apocalyptic number.

19918967 is a deficient number, since it is larger than the sum of its proper divisors (1).

19918967 is an equidigital number, since it uses as much as digits as its factorization.

19918967 is an evil number, because the sum of its binary digits is even.

The product of its digits is 244944, while the sum is 50.

The square root of 19918967 is about 4463.0669947918. The cubic root of 19918967 is about 271.0746697650.

The spelling of 19918967 in words is "nineteen million, nine hundred eighteen thousand, nine hundred sixty-seven".