19664825 has 12 divisors (see below), whose sum is σ = 24603708. Its totient is φ = 15590400.

The previous prime is 19664779. The next prime is 19664833. The reversal of 19664825 is 52846691.

It is a happy number.

It can be written as a sum of positive squares in 6 ways, for example, as 1915456 + 17749369 = 1384^2 + 4213^2 .

It is not a de Polignac number, because 19664825 - 2¹⁰ = 19663801 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 656 + ... + 6305.

It is an arithmetic number, because the mean of its divisors is an integer number (2050309).

Almost surely, 2^19664825 is an apocalyptic number.

It is an amenable number.

19664825 is a deficient number, since it is larger than the sum of its proper divisors (4938883).

19664825 is a wasteful number, since it uses less digits than its factorization.

19664825 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7084 (or 7079 counting only the distinct ones).

The product of its digits is 103680, while the sum is 41.

The square root of 19664825 is about 4434.5039181401. The cubic root of 19664825 is about 269.9168696980.

The spelling of 19664825 in words is "nineteen million, six hundred sixty-four thousand, eight hundred twenty-five".