621603444 has 96 divisors (see below), whose sum is σ = 1866719232. Its totient is φ = 156240000.

The previous prime is 621603443. The next prime is 621603461. The reversal of 621603444 is 444306126.

It is a super-2 number, since 2×621603444² = 772781683185322272, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (621603443) 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, 17794 + ... + 39494.

It is an arithmetic number, because the mean of its divisors is an integer number (19444992).

Almost surely, 2^621603444 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 621603444, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (933359616).

621603444 is an abundant number, since it is smaller than the sum of its proper divisors (1245115788).

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

621603444 is a wasteful number, since it uses less digits than its factorization.

621603444 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21757 (or 21755 counting only the distinct ones).

The product of its (nonzero) digits is 13824, while the sum is 30.

The square root of 621603444 is about 24931.9763356217. The cubic root of 621603444 is about 853.4363514272.

The spelling of 621603444 in words is "six hundred twenty-one million, six hundred three thousand, four hundred forty-four".