644143190 has 16 divisors (see below), whose sum is σ = 1159885440. Its totient is φ = 257562240.

The previous prime is 644143153. The next prime is 644143193. The reversal of 644143190 is 91341446.

It is a happy number.

It is a super-2 number, since 2×644143190² = 829840898446752200, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (644143193) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 20891 + ... + 41529.

It is an arithmetic number, because the mean of its divisors is an integer number (72492840).

Almost surely, 2^644143190 is an apocalyptic number.

644143190 is a deficient number, since it is larger than the sum of its proper divisors (515742250).

644143190 is a wasteful number, since it uses less digits than its factorization.

644143190 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23767.

The product of its (nonzero) digits is 10368, while the sum is 32.

The square root of 644143190 is about 25379.9761623214. The cubic root of 644143190 is about 863.6295091842.

The spelling of 644143190 in words is "six hundred forty-four million, one hundred forty-three thousand, one hundred ninety".