644147850 has 48 divisors (see below), whose sum is σ = 1691463168. Its totient is φ = 161667840.

The previous prime is 644147827. The next prime is 644147851. The reversal of 644147850 is 58741446.

It is a junction number, because it is equal to n+sod(n) for n = 644147799 and 644147808.

It is not an unprimeable number, because it can be changed into a prime (644147851) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 123754 + ... + 128853.

It is an arithmetic number, because the mean of its divisors is an integer number (35238816).

Almost surely, 2^644147850 is an apocalyptic number.

644147850 is an abundant number, since it is smaller than the sum of its proper divisors (1047315318).

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

644147850 is a wasteful number, since it uses less digits than its factorization.

644147850 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 252639 (or 252634 counting only the distinct ones).

The product of its (nonzero) digits is 107520, while the sum is 39.

The square root of 644147850 is about 25380.0679668121. The cubic root of 644147850 is about 863.6315917977.

The spelling of 644147850 in words is "six hundred forty-four million, one hundred forty-seven thousand, eight hundred fifty".