1640425 has 6 divisors (see below), whose sum is σ = 2034158. Its totient is φ = 1312320.

The previous prime is 1640423. The next prime is 1640447. The reversal of 1640425 is 5240461.

It can be written as a sum of positive squares in 3 ways, for example, as 535824 + 1104601 = 732^2 + 1051^2 .

It is not a de Polignac number, because 1640425 - 2¹ = 1640423 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1640396 and 1640405.

It is not an unprimeable number, because it can be changed into a prime (1640423) 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, 32784 + ... + 32833.

2^1640425 is an apocalyptic number.

It is an amenable number.

1640425 is a deficient number, since it is larger than the sum of its proper divisors (393733).

1640425 is an equidigital number, since it uses as much as digits as its factorization.

1640425 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 65627 (or 65622 counting only the distinct ones).

The product of its (nonzero) digits is 960, while the sum is 22.

The square root of 1640425 is about 1280.7907713596. The cubic root of 1640425 is about 117.9375567351.

Adding to 1640425 its reverse (5240461), we get a palindrome (6880886).

The spelling of 1640425 in words is "one million, six hundred forty thousand, four hundred twenty-five".