644030490 has 32 divisors (see below), whose sum is σ = 1554940800. Its totient is φ = 170711744.

The previous prime is 644030477. The next prime is 644030557. The reversal of 644030490 is 94030446.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 59265 + ... + 69284.

It is an arithmetic number, because the mean of its divisors is an integer number (48591900).

Almost surely, 2^644030490 is an apocalyptic number.

644030490 is an abundant number, since it is smaller than the sum of its proper divisors (910910310).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

644030490 is a wasteful number, since it uses less digits than its factorization.

644030490 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 128726.

The product of its (nonzero) digits is 10368, while the sum is 30.

The square root of 644030490 is about 25377.7558109459. The cubic root of 644030490 is about 863.5791390574.

The spelling of 644030490 in words is "six hundred forty-four million, thirty thousand, four hundred ninety".