1664651225 has 12 divisors (see below), whose sum is σ = 2068421184. Its totient is φ = 1328976720.

The previous prime is 1664651213. The next prime is 1664651249. The reversal of 1664651225 is 5221564661.

It is not a de Polignac number, because 1664651225 - 2¹² = 1664647129 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 56189 + ... + 80538.

It is an arithmetic number, because the mean of its divisors is an integer number (172368432).

Almost surely, 2^1664651225 is an apocalyptic number.

It is an amenable number.

1664651225 is a deficient number, since it is larger than the sum of its proper divisors (403769959).

1664651225 is a wasteful number, since it uses less digits than its factorization.

1664651225 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 137224 (or 137219 counting only the distinct ones).

The product of its digits is 86400, while the sum is 38.

The square root of 1664651225 is about 40800.1375610426. The cubic root of 1664651225 is about 1185.1529946609.

The spelling of 1664651225 in words is "one billion, six hundred sixty-four million, six hundred fifty-one thousand, two hundred twenty-five".