1640625403 has 4 divisors (see below), whose sum is σ = 1640801008. Its totient is φ = 1640449800.

The previous prime is 1640625379. The next prime is 1640625457. The reversal of 1640625403 is 3045260461.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1640625403 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1640625703) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 72951 + ... + 92752.

It is an arithmetic number, because the mean of its divisors is an integer number (410200252).

Almost surely, 2^1640625403 is an apocalyptic number.

1640625403 is a deficient number, since it is larger than the sum of its proper divisors (175605).

1640625403 is an equidigital number, since it uses as much as digits as its factorization.

1640625403 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 175604.

The product of its (nonzero) digits is 17280, while the sum is 31.

The square root of 1640625403 is about 40504.6343397888. The cubic root of 1640625403 is about 1179.4235916496.

Adding to 1640625403 its reverse (3045260461), we get a palindrome (4685885864).

The spelling of 1640625403 in words is "one billion, six hundred forty million, six hundred twenty-five thousand, four hundred three".