644022471 has 8 divisors (see below), whose sum is σ = 896031360. Its totient is φ = 410680952.

The previous prime is 644022433. The next prime is 644022473. The reversal of 644022471 is 174220446.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 644022471 - 2²³ = 635633863 is a prime.

It is a super-3 number, since 3×644022471³ (a number of 27 digits) contains 333 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (644022473) 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, 4666761 + ... + 4666898.

It is an arithmetic number, because the mean of its divisors is an integer number (112003920).

Almost surely, 2^644022471 is an apocalyptic number.

644022471 is a deficient number, since it is larger than the sum of its proper divisors (252008889).

644022471 is a wasteful number, since it uses less digits than its factorization.

644022471 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9333685.

The product of its (nonzero) digits is 10752, while the sum is 30.

The square root of 644022471 is about 25377.5978177605. The cubic root of 644022471 is about 863.5755548224.

The spelling of 644022471 in words is "six hundred forty-four million, twenty-two thousand, four hundred seventy-one".