644183034 has 64 divisors (see below), whose sum is σ = 1497968640. Its totient is φ = 182726720.

The previous prime is 644183027. The next prime is 644183039. The reversal of 644183034 is 430381446.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 644182986 and 644183004.

It is not an unprimeable number, because it can be changed into a prime (644183039) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 66832 + ... + 75860.

It is an arithmetic number, because the mean of its divisors is an integer number (23405760).

Almost surely, 2^644183034 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 644183034, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (748984320).

644183034 is an abundant number, since it is smaller than the sum of its proper divisors (853785606).

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

644183034 is a wasteful number, since it uses less digits than its factorization.

644183034 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9115.

The product of its (nonzero) digits is 27648, while the sum is 33.

The square root of 644183034 is about 25380.7610996991. The cubic root of 644183034 is about 863.6473156519.

The spelling of 644183034 in words is "six hundred forty-four million, one hundred eighty-three thousand, thirty-four".