19892989 has 2 divisors, whose sum is σ = 19892990. Its totient is φ = 19892988.

The previous prime is 19892987. The next prime is 19893007. The reversal of 19892989 is 98929891.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19448100 + 444889 = 4410^2 + 667^2 .

It is a cyclic number.

It is not a de Polignac number, because 19892989 - 2¹ = 19892987 is a prime.

It is a super-2 number, since 2×19892989² = 791462022708242, which contains 22 as substring.

Together with 19892987, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (19892987) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9946494 + 9946495.

It is an arithmetic number, because the mean of its divisors is an integer number (9946495).

Almost surely, 2^19892989 is an apocalyptic number.

It is an amenable number.

19892989 is a deficient number, since it is larger than the sum of its proper divisors (1).

19892989 is an equidigital number, since it uses as much as digits as its factorization.

19892989 is an evil number, because the sum of its binary digits is even.

The product of its digits is 839808, while the sum is 55.

The square root of 19892989 is about 4460.1557147705. The cubic root of 19892989 is about 270.9567747401.

The spelling of 19892989 in words is "nineteen million, eight hundred ninety-two thousand, nine hundred eighty-nine".