640889803 has 2 divisors, whose sum is σ = 640889804. Its totient is φ = 640889802.

The previous prime is 640889761. The next prime is 640889861. The reversal of 640889803 is 308988046.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 640889803 - 2¹³ = 640881611 is a prime.

It is not a weakly prime, because it can be changed into another prime (640889903) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 320444901 + 320444902.

It is an arithmetic number, because the mean of its divisors is an integer number (320444902).

Almost surely, 2^640889803 is an apocalyptic number.

640889803 is a deficient number, since it is larger than the sum of its proper divisors (1).

640889803 is an equidigital number, since it uses as much as digits as its factorization.

640889803 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 331776, while the sum is 46.

The square root of 640889803 is about 25315.8014488975. The cubic root of 640889803 is about 862.1730707446.

The spelling of 640889803 in words is "six hundred forty million, eight hundred eighty-nine thousand, eight hundred three".