19378987 has 2 divisors, whose sum is σ = 19378988. Its totient is φ = 19378986.

The previous prime is 19378969. The next prime is 19379011. The reversal of 19378987 is 78987391.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-19378987 is a prime.

It is not a weakly prime, because it can be changed into another prime (19378967) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9689493 + 9689494.

It is an arithmetic number, because the mean of its divisors is an integer number (9689494).

Almost surely, 2^19378987 is an apocalyptic number.

19378987 is a deficient number, since it is larger than the sum of its proper divisors (1).

19378987 is an equidigital number, since it uses as much as digits as its factorization.

19378987 is an evil number, because the sum of its binary digits is even.

The product of its digits is 762048, while the sum is 52.

The square root of 19378987 is about 4402.1570848846. The cubic root of 19378987 is about 268.6026896316.

The spelling of 19378987 in words is "nineteen million, three hundred seventy-eight thousand, nine hundred eighty-seven".