19669987 has 2 divisors, whose sum is σ = 19669988. Its totient is φ = 19669986.

The previous prime is 19669967. The next prime is 19670011. The reversal of 19669987 is 78996691.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-19669987 is a prime.

It is not a weakly prime, because it can be changed into another prime (19669907) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9834993 + 9834994.

It is an arithmetic number, because the mean of its divisors is an integer number (9834994).

Almost surely, 2^19669987 is an apocalyptic number.

19669987 is a deficient number, since it is larger than the sum of its proper divisors (1).

19669987 is an equidigital number, since it uses as much as digits as its factorization.

19669987 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1469664, while the sum is 55.

The square root of 19669987 is about 4435.0859067215. The cubic root of 19669987 is about 269.9404852821.

The spelling of 19669987 in words is "nineteen million, six hundred sixty-nine thousand, nine hundred eighty-seven".