19489897 has 6 divisors (see below), whose sum is σ = 22671978. Its totient is φ = 16705584.

The previous prime is 19489889. The next prime is 19489907. The reversal of 19489897 is 79898491.

It can be written as a sum of positive squares in only one way, i.e., 19263321 + 226576 = 4389^2 + 476^2 .

It is not a de Polignac number, because 19489897 - 2³ = 19489889 is a prime.

It is not an unprimeable number, because it can be changed into a prime (19489807) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 198828 + ... + 198925.

It is an arithmetic number, because the mean of its divisors is an integer number (3778663).

Almost surely, 2^19489897 is an apocalyptic number.

It is an amenable number.

19489897 is a deficient number, since it is larger than the sum of its proper divisors (3182081).

19489897 is an equidigital number, since it uses as much as digits as its factorization.

19489897 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 397767 (or 397760 counting only the distinct ones).

The product of its digits is 1306368, while the sum is 55.

The square root of 19489897 is about 4414.7363454684. The cubic root of 19489897 is about 269.1141383032.

The spelling of 19489897 in words is "nineteen million, four hundred eighty-nine thousand, eight hundred ninety-seven".